The generator matrix

 1  0  1  1  1  0  1  1  2  1  1 X+2  X  1 X+2  1  1  1  2  1  X
 0  1  1  0 X+1  1 X+3  0  1  2  3  1  1 X+2  1  3  0  0  X  X X+2
 0  0  X  0  0  0  0  X  X X+2 X+2  2 X+2  2  X X+2 X+2 X+2 X+2  X  X
 0  0  0  X  0 X+2 X+2  X  2  2  X  2  0  0 X+2 X+2  X  X  0  0 X+2
 0  0  0  0  2  0  0  2  2  0  0  0  0  2  2  0  2  2  0  2  2
 0  0  0  0  0  2  0  0  0  0  0  2  2  2  0  0  2  2  2  0  2
 0  0  0  0  0  0  2  0  0  2  0  0  0  2  2  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 15.

Homogenous weight enumerator: w(x)=1x^0+78x^15+222x^16+294x^17+534x^18+950x^19+1318x^20+1438x^21+1238x^22+970x^23+598x^24+306x^25+146x^26+50x^27+34x^28+10x^29+2x^30+3x^32

The gray image is a code over GF(2) with n=84, k=13 and d=30.
This code was found by Heurico 1.16 in 88.9 seconds.