The generator matrix

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

generates a code of length 18 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 15.

Homogenous weight enumerator: w(x)=1x^0+108x^15+555x^16+776x^17+1376x^18+624x^19+444x^20+152x^21+48x^22+4x^23+8x^24

The gray image is a code over GF(2) with n=144, k=12 and d=60.
This code was found by Heurico 1.16 in 0.031 seconds.