CombinaTexas 2019
CombinaTexas, a combinatorics conference in the SouthCentral United States, is an annual regional conference on Combinatorics, Graph Theory, and Computing. It is dedicated to the enhancement of both the educational and research atmospheres of the community of combinatorialists and graph theorists in Texas and the surrounding states. The aim of the CombinaTexas series is to increase communication between mathematicians in the region, promote the research of the regional combinatorics community, and provide a forum for presentation and discussion of developments in the field of combinatorics.
For more information about the CombinaTexas series, click here.
Basic Information
Texas A&M University,
College Station, TX,
March 2324, 2019. (The Conference will start on Satuday morning and end anound noon of Sunday.)
Registration
Please fill out the registration form.
The deadline to request support and submit contributed talks is February 28th, 2019.
The general registration deadline is March 8th, 2019.
Support
A limited amount of support is available. The conference will book hotel rooms for one night
(March 23) for participants who requested financial aid. (Graduate students and postdocs may need to share
a double room.) In addition, there is a small amount of support for travel expenses, for which we will give
priority to graduate students and recent Ph.Ds with contributed talks. If you are applying for the travel support,
please indicate the estimated amount of airfare.
The application for support, as well as submission of contributed talks, should be done through the online
registration form.
Plenary Speakers
 Ira Gessel, Brandeis University.
 Title: Rook theory and simplicial complexes
 Jessica McDonald, Auburn University.
 Title: Packing and Covering Triangles in Graphs and Digraphs
 Criel Merino, UNAM, Mexico.
 Title: Some heterochromatic theorems for matroids
 Svetlana Poznanovikj, Clemson University.
 Title: Properties of some combinatorial statistics: from permutations to words and labeled trees
 Brendon Rhoades, University of California, San Diego.
 Title: Spanning subspace configurations
 Joel Spencer, New York University.
 Title: Four Discrepancies
Schedule and Abstracts
All the academic activities will be held at Blocker Building on the Texas A&M Campus;
here is an interactive campus map .
Click each title to reveal the abstract, or download the
full schedule.
Saturday, March 23, 2019
08:00am  08:30am 
BLOC 141 
Registration and Breakfast

08:30am  09:30am 
BLOC 166 
Joel Spencer
(New York University)



+ Four Discrepancies



Paul selects $\vec{c_i}\in \{1,+1\}^n$ and
Carole selects $\vec{x}=(x_1,\ldots,x_n)\in \{1,+1\}^n$.
The payoff (which Carole tries to minimize) is
$V=\max_i\vec{x}\cdot\vec{c_i}$.
When $\vec{c_i}\in \{0,1\}^n$ we may interpret the matrix
with columns $\vec{c_i}$ as the indidence matrix of a
family of sets and $V$ is the discrepancy of the family.
We consider four variants of this problem Paul may play
randomly (in which case Carole tries to minimize $E[V]$)
or adversarially. Carole may play OnLine (selecting
$x_i$ after seeing $\vec{c_i}$ or OffLine (seeing all
$\vec{c_i}$ and then selecting $\vec{x}$).

09:30am  10:50am 

Contributed Session I


BLOC 166 
Session A



09:30am  09:50am 
Humberto Bautista Serrano, University of Texas at Tyler


+ Intersection numbers and inconjugate intersection numbers for finite groups


Abstract: In a popular paper of Cohn, the concept of a covering number of a
group was introduced. The covering number of a finite group G is the smallest
number of proper subgroups of G whose settheoretic union is G. Covering
numbers are the subject of prior research by numerous authors, and in this
talk we focus on a dual problem to that of covering numbers of groups, which
involves maximal subgroups of finite groups. In addition, we will compare our
results to some of the wellknown results on covering numbers.
This is joint work by KASSIE ARCHER, HUMBERTO BAUTISTA SERRANO, KAYLA COOK,
L.K. LAUDERDALE, YANSY PEREZ, AND VINCENT VILLALOBOS

09:50am  10:10am 
Andres Carnero, UNAM


+ Homology groups and total domination


Abstract: Let $G$ be a simple graph. A set $S$ of vertices is a total dominating set if each vertex
in $V(G)$ is adjacent to some vertex in $S$. The cardinality of a smallest total dominating set in a graph
$G$ is called the total domination number of $G$ and we will denote it by $\gamma_t(G)$. In this talk, we
will present an upper bound on the the total domination number of $G$ by means of algebraic topology. The
idea is to associate a simplicial complex $I(G)$, the independence complex, to $G$ and give the bound in
terms of its reduced homology groups. In 2002, Meshulam showed that, if $\tilde{H}_q(I(G))\cong 0$, then
$\gamma_t(G)\leq 2q+2$. We will show an improvement to this bound for the cases $q=1,2$ when some additional
restrictions to $\tilde{H}_q(I(G))$ are imposed.

10:10am  10:30am 
Lucas Rusnak, Texas State University


+ The category of incidence structures and generalizing graph theories


Abstract: An incidence structure is a combinatorial multidesign defined as a
quintuple (V, E, I, f, g) of sets
of vertices, edges, incidences, and a morphism pair (f, g) to assign incidences. Through the incidence structure,
many graph theoretic theorems can be extended to integer matrices by examining locally graphic properties of the
associated hypergraphs. We will survey some of my favorite hypergraphic generalizations before examining how closely
the categorical structure of incidence hypergraphs are to wellstudied combinatorial categories. We demonstrate the
category of incidence hypergraphs is the natural category in which “graphlike” combinatorics resides and allows
for a concrete and explicit construction of the quiver exponential.

10:30am  10:50am 
Charles Burnette, Saint Louis University


+ Permutations with equal orders


Abstract: Let $P(n)$ be the probability that two independent, uniformly random permutations of $[n]$ have the same order,
and let $K(n)$ be the probability that they are in the same conjugacy class. Answering a question of Thibault
Godin, we will see in this talk that $P(n) = n^{2 + o(1)}$ and that $\lim\sup \frac{P(n)}{K(n)} = \infty.$
(This is based on joint work with Huseyin Acan, Sean Eberhard, Eric Schmutz, and James Thomas.)



BLOC 164 
Session B



09:30am  09:50am 
Suk Seo, Middle Tennessee State University


+ Faulttolerant distinguishing sets in cubic graphs


Abstract: Assume a graph G models a facility with an intruder or a multiprocessor network with one
malfunctioning processor. We want to use (the minimum possible number of) detectors to be able to
precisely determine the location of the intruder or the malfunctioning processor. Various distinguishing
set parameters have been defined based on the functionality of the detector such as locating dominating sets,
identifying codes, and openlocating dominating sets. In this talk we consider several types of faulttolerant
detectors identified for the openlocatingdominating sets on cubic graphs.

09:50am  10:10am 
Christy Graves, University of Texas at Tyler


+ Uniformly most reliable 2terminal networks


Abstract: Given a fixed amount of resources (vertices and edges), how should they be arranged
to ensure that the network is most reliable? Mathematically, we define the twoterminal reliability
polynomial of a graph with two specified target vertices to be the probability that there exists a
path between the target vertices if each edge operates independently with the same fixed probability.
Given a fixed number of vertices and a fixed number of edges, a graph is uniformly most reliable if
its reliability polynomial is greater than or equal to all other graphs with the same number of
vertices and edges for all probabilities between 0 and 1. We present specific cases for which a
uniformly most reliable graph does not exist as well as cases where there does exist a uniformly
most reliable graph.

10:10am  10:30am 
MartinEduardo FriasArmenta, Univerisdad de Sonora


+ Contractible transformations of graphs and collapsibility


Abstract: In this talk we will give the definition of contractible graph given by Ivashchencko,
we will see the definition of collapsible graph, we will prove that each contractable graph is collapsible
and we will see different results around these concepts.

10:30am  10:50am 
Hector Alfredo HernandezHdez, Universidad de Sonora


+ Programs to calculate Ivashchenko's and colapsibles graphics


Abstract: In this work, programs are presented
for the calculation of a subfamily of Ivashchenko graphics
and collapsible graphics
as well as the required functions
written in C / C ++ language.
A numbering of simple graphs is proposed and its own version is shown
of the canonical labeling algorithm.
At the same time, it will be disseminated to
repository
of the Group of Geometric Structures and Combinatoria.
of the Universidad de Sonora.


10:50am  11:10am 
BLOC 141 
Break

11:10am  12:10pm 
BLOC 166 
Svetlana Poznanovikj
(Clemson University)



+ Properties of some combinatorial statistics: from permutations to words and labeled trees



Since the seminal result of MacMahon on the distribution of the major index over the symmetric group, several
other Mahonian statistics have been found and studied together with partners such as lefttoright maxima,
descents, excedences, etc. Later, Bjorner and Wachs defined a major index for labeled plane forests and
showed that it has the same distribution as the number of inversions. This can be viewed as a generalization
of MacMahon's result for permutations. In this talk I will discuss some of the classical permutation statistics
in the setting of words and labeled forests. We will see what bottomtotop maxima, cyclic bottomtotop maxima,
sorting index, and cycle minima are and show that the pairs (inv, Btmax), (sor, Cyc), and (maj, Cbtmax) are
equidistributed. Even though our results extend the result of Bjorner and Wachs and further generalize
results for permutations, the picture is not complete and I will discuss some ideas on how to improve this.

02:00pm  03:00pm 
BLOC 166 
Brendon Rhoades
(University of California San Diego)



+Spanning subspace configurations



Let $k \leq n$ be positive integers. An ordered tuple of 1dimensional subspaces $(L_1, \dots, L_n)$ of a
fixed $k$dimensional vector space $V$ is a {\em spanning line configuration} if $L_1 + \cdots + L_n = V$ as
vector spaces. I will discuss the geometry and combinatorics of these objects, generalizing classical results
for the {\em flag variety} when $k = n$. I will also describe some (sometimes conjectural) extensions to
higherdimensional subspaces of $V$. Joint with Brendan Pawlowski and Andy Wilson.

03:00pm  04:20pm 

Contributed Session II


BLOC 166 
Session A



03:00pm  03:20pm 
Kassie Archer, University of Texas at Tyler


+ Pattern avoidance and cycle type


Abstract: We say a permutation avoids a given pattern if there is no subsequence
of the permutation that appears in the same relative order as the pattern. Pattern
avoidance for permutations has been widely studied, but it remains open to enumerate
certain sets of patternavoiding permutations with respect to their cycle type. For
example, it is unknown how many cyclic permutations avoid any single pattern of length 3.
In this talk, we discuss what is known and present a result for cycles avoiding certain
pairs of permutations.

03:20pm  03:40pm 
Suho Oh, Texas State University


+ hvector of some Gammoids


Abstract: Hvector comes from a simplicial complex by counting the faces of each dimension and shifting the
sequence. Pure Osequence comes from starting out with monomials of equal degree sum, collecting all their
divisors and counting the monomials of each degree. Stanley has conjectured that hvector of any matroid simplicial
complex is a pure Osequence as well. Gammoids come from describing the set of vertices that can be reached by
vertexdisjoint paths in a directed graph (very different from usual graphic matroids!) By peeling off the layers
of certain polytopes, we show that Stanley's conjecture is true for a small class of gammoids including all cotrasversals.

03:40pm  04:00pm 
Somabha Mukherjee, University of Pennsylvania


+ Limiting Distribution of Quadratic Chaos on Graphs


Abstract: Given i.i.d. observations $X_1, X_2, ... , X_n$ from some distribution $F_n$,
the quadratic chaos of $F_n$ on a sequence of graphs $G_n$ is defined as $T_n(F_n):=\sum_{(i,j)} a_{i,j}(G_n) X_i X_j$,
where $a_{i,j}(G_n)$ is the $(i,j)^{th}$ element of the adjacency matrix of $G_n$.
In this talk, we will provide sufficient conditions under which $T_n(F_n)$ converges weakly, assuming
that the underlying distribution is Bernoulli with mean going to 0. The form of the limiting distribution
is quite general, and covers many important examples as subcases. We will also demonstrate a universality phenomenon,
that allows us to extend our result from the Bernoulli distribution to discrete distributions where
$P(X_1=1)$ accounts for most of $E(X_1)$.

04:00pm  04:20pm 


+


Abstract:



BLOC 164 
Session B



03:00pm  03:20pm 
Rupei Xu, The University of Texas at Dallas


+ Ulam Decompositions in Sparse Graphs


Abstract: Given two graphs $G$ and $H$, each with $n$ vertices and $m$ edges, each graph edge set could be decomposed
into $r$ parts $E_G=E_{G_1}\cup E_{G_2}\cup...\cup E_{G_r}$ and $E_H=E_{H_1}\cup E_{H_2}\cup...\cup E_{H_r}$
such that $G_i$ and $H_i$ are isomorphic, this decomposition is called Ulam Decomposition and the minimum value
of $r$ is defined as $U(X, Y)$. Fan Chung, Ron Graham, Paul Erd\H{o}s, Stan Ulam and Frances Yao did a lot of
contributions to prove the bounds of $U(X, Y)$ and generalized it to multiple pairs or even infinite pairs of
graphs and hypergraphs.
Given two graphs $G$ and $H$, the determination of whether $U(G, H)\leq k$ is an NPcomplete problem, even
when $k=2,$ it is still NPcomplete. In this paper we apply firstorder logic and structural graph theory
tools to show the complexity result of Ulam decompositions in Sparse Graphs.

03:20pm  03:40pm 
Ali Dogan, University of Houston Victoria


+ On Saturated Graphs


Abstract: For a given graph H, we say that a graph G on n vertices is Hsaturated if H is
not a subgraph of G, but for any edge e in the complement of G the graph $G+e$ contains a subgraph
isomorphic to H. The set of all possible values for the size of Hsaturated graphs is called the
edge spectrum for Hsaturated graphs. In this talk, we will discuss the edge spectrum for Hsaturated
graphs when H is a path or a star. In particular, we investigate the second largest Pathsaturated graphs.
This is based on a joint work with Paul Balister.

03:40pm  04:00pm 
JD Nir, University of NebraskaLincoln


+ TuránType Questions about Cliques and Stars


Abstract: The classic extremal problem is that of computing the maximum number
of edges in an $F$free graph. In the case where $F$ is a clique, the extremal
number was determined by Tur\'an. In 2015, Alon and Shikhelman generalized this
problem, asking how many copies of $T$ can be in a graph without a copy of $F$
(which is equivalent to Tur\'an's problem when $T=K_2$ and $F$ is a large clique).
We consider the permutations of this problem when $T$ and $F$ are cliques and stars.

04:00pm  04:20pm 
ChunHung Liu, Texas A&M University


+ Killing subgraphs of large minimum degree in Hminor free graphs randomly


Abstract: Fix a graph H and an integer d, we consider the threshold probability
p(n) such that a random subgraph of an Hminorfree nvertex graph
obtained by keeping each edge independently with probability p(n)
contains a subgraph of minimum degree at least d. Determining such
threshold for all pairs (H,d) is expected to be difficult as it gives
a constantfactor approximation for the maximum number of edges of
Hminorfree nvertex graphs, for any graph H. Joint with Wei, we
determine such threshold asymptotically for a large set of pairs (H,d)
by proving a structural theorem for Hminorfree graphs which
generalizes a result of Ossona de Mendez, Oum and Wood.


04:20pm  04:40pm 
BLOC 141 
Break

04:40pm  05:40pm 
BLOC 166 
Criel Merino
(UNAM)



+ Some heterochromatic theorems for matroids



The antiRamsey number of Erdos, Simonovits and Sos from 1973 has become a classic invariant in Graph Theory.
To extend this invariant to Matroid Theory, we use the heterochromatic number $hc(H)$ of a nonempty hypergraph $H$.
The heterochromatic number of $H$ is the smallest integer $k$ such that for every colouring of the vertices of $H$
with exactly $k$ colours, there is a totally multicoloured hyperedge of $H$.
Given a matroid $M$, there are several hypergraphs over the ground set of $M$ we can consider,
for example, $C(M)$, whose hyperedges are the circuits of $M$, or $B(M)$, whose hyperedges are
the bases of $M$. We determine $hc(C(M))$ for general matroids and characterise the matroids
with the property that $hc(B(M))$ equals the rank of the matroid. We also consider the case
when the hyperedges are the Hamiltonian circuits of the matroid. Finally, we extend the known
result about the antiRamsey number of 3cycles in complete graphs to the heterochromatic number
of 3circuits in projective geometries over finite fields, and we propose a problem very similar to
the famous problem on the antiRamsey number of the $p$cycles.

06:00pm  08:00pm 
BLOC 141 
Conference Dinner (catered)

Sunday, March 24, 2019
08:00am  08:30am 
BLOC 141 
Breakfast

08:30am  09:50am 

Contributed Session III


BLOC 166 
Session A



08:30am  08:50am 
Ahmed Ashraf, University of Western Ontario


+ Tiling character polynomials


Abstract: The conjugacy classes of symmetric group $S_n$ as well as its irreducible characters are indexed by
integer partitions $\lambda \vdash n$. We introduce the class functions on $S_n$ that count the number of
certain tilings of Young diagrams. The counting interpretation gives a uniform expression of these class
functions in the ring of character polynomials, as defined by Murnaghan. A modern treatment of character
polynomials is given in Orellana and Zabrocki. We prove a relation between these combinatorial class
functions in the (virtual) character ring. From this relation, we were able to prove Goupil's generating
function identity, which can then be used to derive Rosas' formula for Kronecker coefficients of hook shape
partitions and two row partitions.

08:50am  09:10am 
Joshua Swanson, University of California, San Diego


+ Cyclotomic generating function asymptotics


Abstract: It is a remarkable fact that the complex roots of many combinatorial generating functions
are each either a root of unity or zero. We call such polynomials \emph{cyclotomic generating functions} and study
the asymptotics of their coefficients by exploiting a beautiful formula for their cumulants.
Examples include the major index on words or standard tableaux, rank for weight space bases in semisimple Lie algebras,
and Hilbert series of total intersections in weighted projective space. We will discuss some of these examples
in detail as time permits. Joint work with Sara Billey and Matja\v{z} Konvalinka.

09:10am  09:30am 
Tri Lai, University of NebraskaLincoln


+ Factorization Theorems for Tiling Enumerations of Regions with Holes


Abstract: We investigate several new factorization theorems in the tiling enumeration. In particular,
we show that the tiling number of a hexagon with an arbitrary number of triangular holes can always
be written as a product of the tiling number of a similar hexagon with some triangular holes shuffled
(the orientation of a triangular hole is changed from uppointing to downpointing, and vice versa) and
tiling numbers of several semihexagons. Intuitively, the shuffling of the triangular holes only changes
the tiling number of the region by a simple factor. This result generalizes a number of known enumerations
of regions with holes in the literature. It also implies a multiparameter generalization of `dual' of
MacMahon's theorem on plane partitions by Ciucu and Krattenthaler in the study of asymptotic tiling enumeration.
Interestingly, similar factorizations also appear in many different types of regions. If time allows, qanalogs
of the factorization theorems and their possible connections to Schur function identities are also discussed.

09:30am  09:50am 
Jacob White, University of Texas Rio Grande Valley


+ Universal Binomial Coefficients


Abstract: Lucasnomial coefficients and qbinomial coefficients are both generalizations of binomial coefficients that:
1) Satisfy a generalized Pascal recurrence,
2) Can be defined as ratios of generalized factorials, and
3) Can be computed as a weighted sum over lattice paths.
We introduce a new generalization of binomial coefficients, which we call universal binomial coefficients. We
prove that any generalized binomial coefficient which satisfies 1) and 2) is a specialization of the universal binomial
coefficients. We also give combinatorial interpretations for universal binomial coefficients.



BLOC 164 
Session B



08:30am  08:50am 
Derek Drumm, Lamar University


+ Constructing a Fulfilled NFL Schedule Using Design Theory Techniques


Abstract: The NFL provides exciting experience for the interested viewer. However, the
process by which the football games are scheduled is not perfect. The construction of a sufficient
NFL schedule must consider many possible restrictions, complicating the process of creation. This
presentation will reinterpret the current NFL schedule restrictions in design and graph theoretic
terms, provide a construction to build a schedule based on this reinterpretation, and then utilize
the construction to build a possible NFL schedule for 2019.

08:50am  09:10am 
Caleb Ji, Washington University in St. Louis


+ Distinguishing numbers and generalizations


Abstract: The distinguishing number of a graph was introduced by Albertson and Collins as a
measure of the amount of symmetry contained in the graph. Tymoczko extended this definition
to faithful group actions on sets; taking the set to be the vertex set of a graph and the group to
be the automorphism group of the graph allows one to recover the previous definition. In this
talk, I will first illustrate some techniques for computing this number and apply them to answer
some hitherto open questions. Then I will show how this concept can be extended to partitions,
which produces a new partially ordered set on the partitions of a number. Finally I will introduce
a symmetric function generalization of this notion and end with some open questions regarding
it.

09:10am  09:30am 
Pani Seneviratne, Texas A&M UniversityCommerce


+ Circulant graphs and their codes


Abstract: In this talk we will explorer linear codes obtained from circulant graphs. Connections between parameters of
these codes and the defining set of the graph will be discussed.

09:30am  09:50am 
Esmaeil Parsa, The University of Montana


+ Aspects of Unique DColorability for Digraphs


Abstract: n this talk we show that the two definitions of uniquely Dcolorable digraphs that are
either in terms of automorphisms or by vertex partitions are not always equivalent, and
study conditions under which they are equivalent. In response to the question that for
what portion of digraphs the forementioned conditions hold, using probabilistic method
we prove that asymptotically almost surely every random digraph is a core for which these
conditions do not hold.


09:50am  10:10am 
BLOC 141 
Break

10:10am  11:10am 
BLOC 166 
Jessica McDonald
(Auburn University)



+ Packing and Covering Triangles in Graphs and Digraphs



In the 1980’s, Tuza conjectured that that if a graph G has at most t pairwise
edgedisjoint triangles, then there exists a set of at most $2t$ edges whose deletion
makes the graph trianglefree. This conjecture is still wide open, and we will discuss
some of what is known, including tight fractional approximations. We will also highlight
new work (joint with Greg Puelo and Craig Tennenhouse) on a digraph analog of Tuza’s Conjecture.

11:10am  12:10pm 
BLOC 166 
Ira Gessel
(Brandeis University)



+ Rook theory and simplicial complexes



Rook theory deals with placements of nonattacking rooks on a board—a subset of
$[n] \times [n]$, where $[n]=\{1,2, …, n\}$. The rook numbers of a board count placements of
$k$ nonattacking rooks on the board. The hit numbers of the board count placements of
n nonattacking rooks on $[n] \times [n]$ in which $k$ of the rooks lie on the board.
In other words, the hit numbers count permutations $\pi$ according to the number
of pairs $(i, \pi(i))$ on the board.The fundamental identity of rook theory relates
the rook numbers and hit numbers of a board.
The sets of nonattacking rook placement in $[n] \times [n]$ form a simplicial complex
with the property that any two faces of the same size are covered by the same number
of faces, and this property is all we need to prove the fundamental identity. Thus we
can generalize the fundamental identity to other simplicial complexes with the same
property. More generally, we can generalize it to simplicial posets . Interesting
examples include matchings and trees of several types, including ordered and $k$ary.
In this context we also have an analogue of the factorial rook polynomial of Goldman,
Joichi, and White, and of its reciprocity theorem, which relates the rook numbers of a
board to the rook numbers of a complementary board.

Location, Transportation, Parking
All the activities will be held at Blocker Building on
the campus of Texas A&M University.
The Northside Garage (NSG) is located directly across from the Blocker Building (BLOC) and has space for visitor parking. During the weekend, you can also park for free at any unreserved space in a numbered lot, such as Lot 50 and Lot 51. The interactive campus map also lists available parking lots.
Texas A&M University is located in College Station, Texas, which by automobile lies about 1 hour and 45 minutes northwest of Houston, 1 hour and 45 minutes east of Austin, and 3 hours south of Dallas. Easterwood Airport in College Station is served by American Airlines (connecting to Dallas) and United Airlines (connecting to Houston). There is also a shuttle service from Bush Intercontinental Airport and Hobby Airport in Houston and a shuttle service from AustinBergstrom Airport.
Hotels
Hotel reservations for registered participants who receive financial support will be arranged and billed through the Mathematics Department. Details of your reservation will be sent to the provided email address at least one weeks prior to the conference.
Participants will be housed at the The George at College Station or Cavalry Court College Station . Both are in the new Century Square and within walking distance to Blocker.
Graduate students should expect to share a room. If you are not receiving financial support from the conference, you can stay in any hotel in town. Below are some hotels that are within walking distance to the conference site. Please check the rate and availability with the hotels directly.
 Home2 Suites by Hilton College Station , 300 Texas Ave, College Station, TX 77840
 La Quinta Inn College Station, 607 Texas Ave, College Station, TX 77840
 Fairfield Inn & Suites by Marriott Bryan College Station , 4613 Texas Ave, Bryan, TX 77802
 Embassy Suites by Hilton College Station, 201 University Dr E, College Station, TX 77840
 Econo Lodge, 104 Texas Ave. South, College Station, TX 77840
Warning: Please be aware of a new scam, a "room poacher" email, which pretends to be
the housing bureau for CombinaTexas. This is a new scam  described on P285 of the February Notices. They
were from: ops@btravelmanagement.com . Please ignore that email if you receive it.
If you receive financial aid from CombinaTexas'19, all the hotel reservation will be handled by the Math Dept of
TAMU. Please contact the organizers if you have any questions. Otherwise you should make your own reservation.
There is no third party that does the housing reservation for CombinaTexas.
Resources
A map of Texas A&M, and driving directions from the College Station airport.
A list of former CombinaTexas conferences.
Acknowledgement:
This conference is supported in part by National Science Foundation, the Combinatorics Foundation,
and the Department of Mathematics at Texas A&M University.
Organizers
Yue Cai (Texas A&M University)
Laura Matusevich (Texas A&M University)
Catherine Yan (Texas A&M University)