The generator matrix

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

generates a code of length 64 over Z16 who´s minimum homogenous weight is 58.

Homogenous weight enumerator: w(x)=1x^0+409x^58+1166x^59+1911x^60+3122x^61+3509x^62+4586x^63+3992x^64+4354x^65+3485x^66+2850x^67+1611x^68+880x^69+423x^70+230x^71+124x^72+74x^73+22x^74+16x^75+2x^77+1x^80

The gray image is a code over GF(2) with n=512, k=15 and d=232.
This code was found by Heurico 1.16 in 9.9 seconds.