The generator matrix

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

generates a code of length 31 over GR(64,4) who´s minimum homogenous weight is 204.

Homogenous weight enumerator: w(x)=1x^0+168x^204+14112x^205+11760x^206+147x^208+1344x^210+1008x^212+47040x^213+23520x^214+294x^216+21504x^217+9408x^218+2408x^220+89376x^221+39984x^222+7x^224+21x^240+42x^248

The gray image is a code over GF(8) with n=248, k=6 and d=204.
This code was found by Heurico 1.16 in 72.2 seconds.