The generator matrix

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

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+84x^18+24x^19+139x^20+80x^21+88x^22+24x^23+40x^24+12x^26+19x^28+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 7.54 seconds.