The generator matrix
1 0 1 1 1 1 1 1 1 0 1 1 1 0 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+1)X+1 (a+1)X+a+1 1 X 1 (a+1)X+1 aX+a+1
0 0 (a+1)X 0 X X (a+1)X X (a+1)X X 0 aX aX 0 X X aX 0
0 0 0 X aX X aX (a+1)X (a+1)X 0 X (a+1)X aX (a+1)X 0 (a+1)X X (a+1)X
generates a code of length 18 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 46.
Homogenous weight enumerator: w(x)=1x^0+192x^46+132x^48+576x^50+360x^52+1344x^54+480x^56+960x^58+27x^64+24x^68
The gray image is a linear code over GF(4) with n=72, k=6 and d=46.
This code was found by Heurico 1.16 in 2.4 seconds.