The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1  1  0  1  1  1  1  X  1  1  1 (a+1)X  1  1
 0  1  1  a (a+1)X+a+1  0 (a+1)X+1  a (a+1)X+a+1  1  0  a (a+1)X+1  1  X  X (a+1)X+a+1 X+a  1 aX+a aX+a+1 (a+1)X+1  1 aX+a+1 aX+1
 0  0 (a+1)X  0  X  X (a+1)X  X (a+1)X  X  0  0  X  X aX  0 (a+1)X  0 aX aX aX aX  0  X  X
 0  0  0  X aX  X aX (a+1)X (a+1)X  0  X (a+1)X  0 aX  X aX aX  0  0 (a+1)X aX  0 (a+1)X (a+1)X  X

generates a code of length 25 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+594x^68+918x^72+1569x^76+969x^80+24x^84+21x^92

The gray image is a linear code over GF(4) with n=100, k=6 and d=68.
This code was found by Heurico 1.16 in 0.338 seconds.