The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1  1  1  X  1  1  1  1  X  1  1  1  1  1  1  1  1  1  1  0  X  1  1 a*X  1  1 a*X  1  1  1  1  1  1 a*X a*X  0  X  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1 a^2*X a^2*X a^2*X
 0  1  1  a a^2*X+a^2  0 a^2*X+1 a^2*X+a^2  a  1 a*X+a^2  X a^2*X+1 X+a  1  X  1 X+a a*X+a^2  1  0  X a^2*X+1 a*X+1 a*X+1 X+a a*X+a a*X+a a^2*X+a^2 a*X+a^2  1  1 a*X X+a^2  1 a*X X+a^2  1 a*X+1  a a*X  1 a*X+a X+a^2  1  1  1  1  0  X a*X a^2*X+1  1 a*X+1  a X+a a*X+a a^2*X+a^2 a*X+a^2 X+a^2 a^2*X a^2*X a^2*X a^2*X X+1 X+1 X+1 X+1 a^2*X+a a^2*X+a a^2*X+a a^2*X+a a^2 a^2 a^2 a^2  0  0  X  X a^2*X+1 a^2*X+1 a*X+1 a*X+1  1  1  1
 0  0 a^2*X a*X  X  X  0 a^2*X  0 a*X a*X a^2*X a*X  X  X a*X  X a^2*X  0 a^2*X a*X  X  X a^2*X  0 a*X  0  X a*X a^2*X a^2*X  0 a^2*X  0  X  0  X a*X a*X a^2*X  X  0 a*X a^2*X a^2*X  0  X a*X a^2*X  0 a*X a^2*X a*X  X  X  0 a^2*X  0  X a*X a^2*X a*X  X  0  0  X a*X a^2*X a^2*X a*X  X  0 a^2*X a*X  X  0  0  X a^2*X a*X  0  X a^2*X a*X a^2*X a*X  X

generates a code of length 87 over F4[X]/(X^2) who´s minimum homogenous weight is 257.

Homogenous weight enumerator: w(x)=1x^0+144x^257+180x^260+480x^261+60x^264+144x^265+6x^268+6x^284+3x^288

The gray image is a linear code over GF(4) with n=348, k=5 and d=257.
This code was found by Heurico 1.16 in 0.141 seconds.