The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2
 0  1 2a^2+3  a 3a^2+2 2a^2+3a+1 a^2+3a a^2+3a+3 3a^2+2a+3  2 2a^2+2a+3 a+2 3a^2+2a+2 2a^2+3a+3 a^2+a a^2+3a+1 3a^2+3  1

generates a code of length 18 over GR(64,4) who´s minimum homogenous weight is 120.

Homogenous weight enumerator: w(x)=1x^0+1008x^120+3087x^128

The gray image is a code over GF(8) with n=144, k=4 and d=120.
This code was found by Heurico 1.16 in 0.00145 seconds.