The generator matrix

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

generates a code of length 52 over GR(64,4) who´s minimum homogenous weight is 320.

Homogenous weight enumerator: w(x)=1x^0+245x^320+1484x^328+2352x^336+448x^343+3290x^344+9408x^351+3682x^352+65856x^359+4613x^360+153664x^367+5117x^368+4872x^376+3710x^384+2289x^392+945x^400+140x^408+28x^416

The gray image is a code over GF(8) with n=416, k=6 and d=320.
This code was found by Heurico 1.16 in 32.3 seconds.