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

generates a code of length 43 over GR(64,4) who´s minimum homogenous weight is 284.

Homogenous weight enumerator: w(x)=1x^0+3808x^284+224x^287+1372x^288+4032x^289+6944x^290+6496x^291+21840x^292+448x^294+3136x^295+7112x^296+13440x^297+15232x^298+8512x^299+32704x^300+3136x^302+10976x^303+16947x^304+25536x^305+24416x^306+13664x^307+42000x^308+84x^312+49x^320+28x^328+7x^336

The gray image is a code over GF(8) with n=344, k=6 and d=284.
This code was found by Heurico 1.16 in 44 seconds.