The generator matrix

 1  0  1  1  1  2  1 X+2  1  1  1  2  1  1  1  1  1  1  2  X  X
 0  1  1 X+2 X+1  1  2  1  3  2  1  1  2 X+2  X X+2 X+1  1  1  1  2
 0  0  X  0  2 X+2  X  0  2 X+2 X+2  X  2  0  X  X  2  0  2 X+2  X
 0  0  0  2  2  0  2  2  0  0  2  2  2  0  0  2  0  2  2  2  2

generates a code of length 21 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+52x^18+104x^19+88x^20+56x^21+60x^22+88x^23+41x^24+8x^25+8x^26+6x^28

The gray image is a code over GF(2) with n=84, k=9 and d=36.
This code was found by Heurico 1.16 in 0.00634 seconds.