The generator matrix

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

generates a code of length 23 over GR(64,4) who´s minimum homogenous weight is 136.

Homogenous weight enumerator: w(x)=1x^0+112x^136+224x^140+168x^141+672x^144+1344x^147+4704x^148+2184x^149+735x^152+3584x^154+18816x^155+32928x^156+9464x^157+777x^160+25088x^162+65856x^163+76832x^164+16856x^165+798x^168+854x^176+147x^184

The gray image is a code over GF(8) with n=184, k=6 and d=136.
This code was found by Heurico 1.16 in 4.54 seconds.