The generator matrix

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

generates a code of length 18 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 17.

Homogenous weight enumerator: w(x)=1x^0+12x^17+35x^18+8x^19+3x^20+4x^21+1x^22

The gray image is a code over GF(2) with n=144, k=6 and d=68.
This code was found by Heurico 1.16 in 1.05e-007 seconds.