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

generates a code of length 58 over GR(64,4) who´s minimum homogenous weight is 376.

Homogenous weight enumerator: w(x)=1x^0+105x^376+644x^384+819x^392+616x^400+28672x^406+497x^408+406x^416+378x^424+266x^432+224x^440+77x^448+49x^456+14x^464

The gray image is a code over GF(8) with n=464, k=5 and d=376.
This code was found by Heurico 1.16 in 0.605 seconds.