The generator matrix

 1  0  0  0  1  1  1  1 12  1  2  6  6  1  1  1 12  0  1 14  1  6 10  1  1  1  1  4 14  1  1 10 10  2  1  1  1  6  1  1  1  0  1  1  1  4  4  1  1  1  4  1  8  1 14  1  1  1  1  0  4  6  1  4 10  1 12  1
 0  1  0  0  2  5  9  4  1 15  1  2  1  2  3  4  1  1  1  0 10  1  2  4  0  7 15  1  0  1  4  1  1  1  1  8  5  1  8 13  6  8 10 12 10  1  1  2  7  1 14  0 10 13  1  7  5 12 15  1  1  1  3  8 14 10 14  0
 0  0  1  0  0  4  1  5  7  5  0  1  7 11  2  6  1 14  2 10  9  8  1  5  4  9  7  7  1  6 15 15 14  3  4 14  3 12  1 13 10  1  2 11 13 10 14 12  7 14  1 12  1  0 10  6  1 12  4  5  4  5 12  1  4 13  1  0
 0  0  0  1  1  7  4  1  7 11  1  9  2 12  2  7 14  1 10  1  7 14  0 10  6  4 11  9  7 13  7  0 10  5 12 13  4 11  0 15  3 10  2  8  9  2  3  2 10  5 11 13 15  2 13 10  5 12 11  1  3  3 15  6  1  2  3  4
 0  0  0  0  4  0  0  0  0  0  0  0  0  0  0  0  0  4 12  4 12  4 12  4 12  8 12  8  4  8  4 12  8  8  8  4 12  8 12  4  8  4  4 12  8  0 12  8  8 12  4  4  0  8  8 12  8  4  4  0  8 12  8  4  0  4 12  4

generates a code of length 68 over Z16 who´s minimum homogenous weight is 59.

Homogenous weight enumerator: w(x)=1x^0+94x^59+717x^60+2336x^61+4671x^62+8776x^63+13825x^64+20272x^65+28378x^66+33706x^67+35948x^68+34406x^69+28522x^70+20898x^71+13843x^72+8220x^73+4120x^74+2056x^75+899x^76+228x^77+127x^78+64x^79+10x^80+6x^81+6x^82+4x^83+4x^84+2x^85+2x^87+1x^88+2x^89

The gray image is a code over GF(2) with n=544, k=18 and d=236.
This code was found by Heurico 1.16 in 617 seconds.