The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  X  1  X  1  0  2  1  2
 0  X  0  X  0  2  X X+2  0  2  X X+2  0  X  X X+2  X  X  X  0  2
 0  0  X  X  0  X X+2  2  0  X  X  0  2 X+2  X  0  0  2 X+2  X  2
 0  0  0  2  0  0  2  0  2  2  0  2  2  0  0  0  2  2  0  2  2
 0  0  0  0  2  2  2  2  2  2  0  2  0  2  2  2  2  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+113x^18+160x^20+147x^22+58x^24+23x^26+4x^28+5x^30+1x^32

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 13.6 seconds.