The generator matrix

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

generates a code of length 86 over GR(16,4) who´s minimum homogenous weight is 251.

Homogenous weight enumerator: w(x)=1x^0+840x^251+276x^252+792x^255+375x^256+708x^259+222x^260+228x^263+12x^264+264x^267+36x^268+72x^271+48x^272+108x^275+39x^276+60x^279+12x^280+3x^308

The gray image is a code over GF(4) with n=344, k=6 and d=251.
This code was found by Heurico 1.16 in 111 seconds.