The generator matrix

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

generates a code of length 47 over GR(64,4) who´s minimum homogenous weight is 318.

Homogenous weight enumerator: w(x)=1x^0+4480x^318+1323x^320+8960x^326+994x^328+15232x^334+1757x^336+7x^368+14x^376

The gray image is a code over GF(8) with n=376, k=5 and d=318.
This code was found by Heurico 1.16 in 0.164 seconds.