The generator matrix

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

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+184x^19+171x^20+192x^21+118x^22+96x^23+71x^24+32x^25+33x^26+8x^27+5x^28

The gray image is a code over GF(2) with n=84, k=10 and d=36.
This code was found by Heurico 1.16 in 0.0134 seconds.