The generator matrix

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

generates a code of length 87 over GR(16,4) who´s minimum homogenous weight is 248.

Homogenous weight enumerator: w(x)=1x^0+375x^248+276x^249+444x^251+1794x^252+480x^253+660x^255+2052x^256+624x^257+648x^259+1863x^260+600x^261+504x^263+1458x^264+348x^265+264x^267+1164x^268+420x^269+228x^271+813x^272+144x^273+264x^275+471x^276+120x^277+48x^279+213x^280+48x^281+12x^283+36x^284+12x^285

The gray image is a code over GF(4) with n=348, k=7 and d=248.
This code was found by Heurico 1.16 in 1.62 seconds.