The generator matrix

 1  1  1  1  1  1  X  0  1  1  X  1  1  0  1  1  X  1  X  X  1
 0  X  0 X^2+X  0 X^2+X  X  X  0 X^2+X  X  0 X^2  X X^2+X X^2+X  0 X^2+X X^2+X X^2+X X^2+X
 0  0 X^2  0  0  0  0  0  0  0  0  0 X^2  0  0  0 X^2 X^2 X^2  0 X^2
 0  0  0 X^2  0  0  0  0  0  0  0  0  0  0  0 X^2 X^2 X^2  0 X^2 X^2
 0  0  0  0 X^2  0  0  0  0  0  0  0 X^2  0 X^2 X^2  0 X^2 X^2  0  0
 0  0  0  0  0 X^2  0  0  0  0  0  0  0 X^2 X^2  0 X^2 X^2  0 X^2  0
 0  0  0  0  0  0 X^2  0  0  0  0 X^2 X^2 X^2  0  0 X^2  0 X^2  0  0
 0  0  0  0  0  0  0 X^2  0  0  0 X^2 X^2 X^2  0  0  0  0  0 X^2 X^2
 0  0  0  0  0  0  0  0 X^2  0  0 X^2  0  0 X^2 X^2  0 X^2  0  0 X^2
 0  0  0  0  0  0  0  0  0 X^2  0 X^2 X^2  0  0 X^2 X^2  0  0 X^2  0
 0  0  0  0  0  0  0  0  0  0 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2  0

generates a code of length 21 over Z2[X]/(X^3) who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+134x^12+64x^14+826x^16+256x^17+832x^18+2048x^19+2406x^20+3584x^21+1728x^22+2048x^23+1432x^24+256x^25+448x^26+274x^28+45x^32+2x^36

The gray image is a linear code over GF(2) with n=84, k=14 and d=24.
This code was found by Heurico 1.16 in 2.2 seconds.