The generator matrix

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

generates a code of length 47 over GR(64,4) who´s minimum homogenous weight is 304.

Homogenous weight enumerator: w(x)=1x^0+497x^304+392x^306+112x^308+672x^309+1120x^311+3976x^312+2744x^314+2352x^316+6048x^317+3360x^319+9289x^320+5544x^322+16464x^324+28896x^325+11424x^327+23562x^328+11368x^330+38416x^332+50400x^333+12768x^335+22904x^336+8624x^338+546x^344+322x^352+238x^360+91x^368+14x^376

The gray image is a code over GF(8) with n=376, k=6 and d=304.
This code was found by Heurico 1.16 in 10.4 seconds.