The generator matrix

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

generates a code of length 15 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 35.

Homogenous weight enumerator: w(x)=1x^0+468x^35+315x^36+948x^37+1392x^38+1860x^39+2235x^40+3204x^41+2640x^42+5724x^43+6939x^44+9180x^45+5904x^46+8748x^47+6843x^48+5100x^49+2352x^50+1632x^51+33x^52+9x^56+9x^60

The gray image is a linear code over GF(4) with n=60, k=8 and d=35.
This code was found by Heurico 1.16 in 61.1 seconds.