pu7 = c[0]^28 + t^2*(x1^2 + x1*x2)*c[0]^27*c[1] + 
   t^4*((x1^3*x2 + x1^2*x2^2 + 2*x1^2*x2*x3 + x1*x2*x3*x4)*c[0]^26*c[1]^2 + 
      (x1^4 + x1^2*x2^2)*c[0]^27*c[2]) + 
   t^6*((x1^3*x2^3 + x1^4*x2*x3 + 2*x1^3*x2^2*x3 + 2*x1^2*x2^2*x3^2 + 
         2*x1^3*x2*x3*x4 + 3*x1^2*x2^2*x3*x4 + 2*x1^2*x2*x3*x4*x5 + 
         x1*x2*x3*x4*x5*x6)*c[0]^25*c[1]^3 + 
      (x1^5*x2 + 2*x1^4*x2^2 + x1^4*x2*x3 + x1^3*x2^2*x3 + 
         x1^2*x2^2*x3^2 + x1^2*x2^2*x3*x4)*c[0]^26*c[1]*c[2] + 
      (x1^6 + x1^3*x2^3)*c[0]^27*c[3]) + 
   t^8*((x1^4*x2^3*x3 + x1^4*x2^2*x3^2 + 2*x1^3*x2^3*x3^2 + x1^5*x2*x3*x4 + 
         2*x1^4*x2^2*x3*x4 + 3*x1^3*x2^3*x3*x4 + 4*x1^3*x2^2*x3^2*x4 + 
         3*x1^2*x2^2*x3^2*x4^2 + 2*x1^4*x2*x3*x4*x5 + 
         5*x1^3*x2^2*x3*x4*x5 + 5*x1^2*x2^2*x3^2*x4*x5 + 
         2*x1^3*x2*x3*x4*x5*x6 + 4*x1^2*x2^2*x3*x4*x5*x6 + 
         2*x1^2*x2*x3*x4*x5*x6*x7)*c[0]^24*c[1]^4 + 
      (x1^5*x2^3 + x1^4*x2^4 + x1^6*x2*x3 + 3*x1^5*x2^2*x3 + 
         2*x1^4*x2^3*x3 + 2*x1^4*x2^2*x3^2 + 2*x1^3*x2^3*x3^2 + 
         x1^5*x2*x3*x4 + 4*x1^4*x2^2*x3*x4 + x1^3*x2^3*x3*x4 + 
         3*x1^3*x2^2*x3^2*x4 + x1^2*x2^2*x3^2*x4^2 + x1^4*x2*x3*x4*x5 + 
         x1^3*x2^2*x3*x4*x5 + 2*x1^2*x2^2*x3^2*x4*x5 + x1^2*x2^2*x3*x4*x5*x6
         )*c[0]^25*c[1]^2*c[2] + 
      (x1^6*x2^2 + x1^4*x2^4 + 2*x1^4*x2^2*x3^2 + x1^2*x2^2*x3^2*x4^2)*
       c[0]^26*c[2]^2 + (x1^7*x2 + x1^6*x2^2 + x1^5*x2^3 + x1^6*x2*x3 + 
         x1^4*x2^3*x3 + x1^3*x2^3*x3^2 + x1^3*x2^3*x3*x4)*c[0]^26*c[1]*c[3] + 
      (x1^8 + x1^4*x2^4)*c[0]^27*c[4])
 
pu7point = 1 + t^2*(x1^2 + x1*x2) + 
   t^4*(x1^4 + x1^3*x2 + 2*x1^2*x2^2 + 2*x1^2*x2*x3 + x1*x2*x3*x4) + 
   t^6*(x1^6 + x1^5*x2 + 2*x1^4*x2^2 + 2*x1^3*x2^3 + 2*x1^4*x2*x3 + 
      3*x1^3*x2^2*x3 + 3*x1^2*x2^2*x3^2 + 2*x1^3*x2*x3*x4 + 
      4*x1^2*x2^2*x3*x4 + 2*x1^2*x2*x3*x4*x5 + x1*x2*x3*x4*x5*x6) + 
   t^8*(x1^8 + x1^7*x2 + 2*x1^6*x2^2 + 2*x1^5*x2^3 + 3*x1^4*x2^4 + 
      2*x1^6*x2*x3 + 3*x1^5*x2^2*x3 + 4*x1^4*x2^3*x3 + 5*x1^4*x2^2*x3^2 + 
      5*x1^3*x2^3*x3^2 + 2*x1^5*x2*x3*x4 + 6*x1^4*x2^2*x3*x4 + 
      5*x1^3*x2^3*x3*x4 + 7*x1^3*x2^2*x3^2*x4 + 5*x1^2*x2^2*x3^2*x4^2 + 
      3*x1^4*x2*x3*x4*x5 + 6*x1^3*x2^2*x3*x4*x5 + 7*x1^2*x2^2*x3^2*x4*x5 + 
      2*x1^3*x2*x3*x4*x5*x6 + 5*x1^2*x2^2*x3*x4*x5*x6 + 
      2*x1^2*x2*x3*x4*x5*x6*x7)
 
pu7line = c[0]^28 + 2*t^2*c[0]^27*c[1] + 
   t^4*(5*c[0]^26*c[1]^2 + 2*c[0]^27*c[2]) + 
   t^6*(14*c[0]^25*c[1]^3 + 7*c[0]^26*c[1]*c[2] + 2*c[0]^27*c[3]) + 
   t^8*(37*c[0]^24*c[1]^4 + 27*c[0]^25*c[1]^2*c[2] + 5*c[0]^26*c[2]^2 + 
      7*c[0]^26*c[1]*c[3] + 2*c[0]^27*c[4])
 
pu7total = 1 + 2*t^2 + 7*t^4 + 23*t^6 + 78*t^8