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

generates a code of length 81 over GR(16,4) who´s minimum homogenous weight is 236.

Homogenous weight enumerator: w(x)=1x^0+960x^236+1269x^240+912x^244+324x^248+276x^252+168x^256+108x^260+72x^264+3x^272+3x^288

The gray image is a code over GF(4) with n=324, k=6 and d=236.
This code was found by Heurico 1.16 in 0.312 seconds.