The generator matrix

 1  0  0  0  0  0  0  1  1  1  1  1  1  X  1  X  X  1  1  0  1
 0  1  0  0  0  0  0  0  0  0  0  0  0  1 X+1  X  1  X X+1  1  X
 0  0  1  0  0  0  0  0  1  X  0  0  1  1 X+1  1 X+1  1  1  1  0
 0  0  0  1  0  0  0  0  1 X+1  X  1  X X+1  0 X+1  0  1  X X+1  0
 0  0  0  0  1  0  0  0  1  1 X+1  X  X  1  X  X  X X+1  1 X+1  0
 0  0  0  0  0  1  0  1  1  0  X  X  0  1  X  0 X+1  1  1 X+1  0
 0  0  0  0  0  0  1  1  X  0  1 X+1  1 X+1 X+1 X+1 X+1  1 X+1 X+1  1
 0  0  0  0  0  0  0  X  0  X  0  X  X  X  0  0  X  0  X  X  0

generates a code of length 21 over Z2[X]/(X^2) who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+111x^12+232x^13+454x^14+704x^15+1253x^16+1750x^17+2591x^18+3412x^19+3779x^20+4236x^21+3788x^22+3300x^23+2582x^24+1800x^25+1270x^26+764x^27+453x^28+172x^29+86x^30+12x^31+12x^32+2x^33+3x^34+1x^36

The gray image is a linear code over GF(2) with n=42, k=15 and d=12.
This code was found by Heurico 1.16 in 19.1 seconds.