The generator matrix

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

generates a code of length 91 over GR(16,4) who´s minimum homogenous weight is 261.

Homogenous weight enumerator: w(x)=1x^0+612x^261+912x^262+360x^263+51x^264+1236x^265+1224x^266+384x^267+75x^268+1368x^269+1428x^270+540x^271+15x^272+1128x^273+1056x^274+408x^275+33x^276+972x^277+948x^278+216x^279+27x^280+684x^281+564x^282+216x^283+21x^284+432x^285+432x^286+132x^287+12x^288+384x^289+252x^290+48x^291+15x^292+72x^293+72x^294+6x^296+24x^297+24x^298

The gray image is a code over GF(4) with n=364, k=7 and d=261.
This code was found by Heurico 1.16 in 39.1 seconds.