The generator matrix

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

generates a code of length 51 over GR(16,4) who´s minimum homogenous weight is 147.

Homogenous weight enumerator: w(x)=1x^0+972x^147+357x^148+852x^151+324x^152+504x^155+132x^156+360x^159+123x^160+252x^163+84x^164+132x^167+3x^180

The gray image is a code over GF(4) with n=204, k=6 and d=147.
This code was found by Heurico 1.16 in 9.52 seconds.