The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  X  1  X  1  1  1  1  1  1  1
 0  X  0  0  0  0  0  0  X  0  X  X  0  0  X  0  X  X  0  X  X  X  0
 0  0  X  0  0  0  0  0  X  X  X  0  0  X  X  X  X  0  X  X  0  0  0
 0  0  0  X  0  0  0  X  0  X  0  X  0  X  X  0  0  X  0  X  X  X  X
 0  0  0  0  X  0  0  X  0  0  X  X  0  X  0  X  X  0  0  X  0  X  X
 0  0  0  0  0  X  0  X  X  0  X  0  X  0  0  0  X  0  X  X  0  X  0
 0  0  0  0  0  0  X  X  X  0  0  X  X  X  X  X  X  0  X  0  X  X  0

generates a code of length 23 over Z2[X]/(X^2) who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+20x^18+30x^20+32x^21+22x^22+64x^23+18x^24+32x^25+11x^26+10x^28+10x^30+5x^32+1x^42

The gray image is a linear code over GF(2) with n=46, k=8 and d=18.
This code was found by Heurico 1.16 in 0.0916 seconds.