The generator matrix

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

generates a code of length 50 over GR(64,4) who´s minimum homogenous weight is 336.

Homogenous weight enumerator: w(x)=1x^0+63x^336+504x^337+336x^338+560x^339+6272x^342+196x^344+3024x^345+1120x^346+1120x^347+1792x^350+98x^352+7224x^353+2128x^354+1904x^355+6272x^358+91x^360+42x^368+21x^376

The gray image is a code over GF(8) with n=400, k=5 and d=336.
This code was found by Heurico 1.16 in 0.17 seconds.