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

generates a code of length 41 over GR(64,4) who´s minimum homogenous weight is 248.

Homogenous weight enumerator: w(x)=1x^0+539x^248+1785x^256+2674x^264+3745x^272+3584x^273+4634x^280+50176x^281+5593x^288+175616x^289+5796x^296+4795x^304+2387x^312+721x^320+98x^328

The gray image is a code over GF(8) with n=328, k=6 and d=248.
This code was found by Heurico 1.16 in 24.1 seconds.