The generator matrix

 1  0  0  0  1  1  1  2  1  1  6  1  1  4  2  0  2  2  1  1  0  6  1  1  0  1  1  1  1  2  4  2  1  4  0  1  2  1  1  1  1  4  2  1  1  1  0  1  2  6  1  6  1  1  1  4  2  4  1  1  1  0  1  1
 0  1  0  0  2  4  6  6  1  7  1  5  3  1  1  1  1  0  7  2  4  1  6  0  1  7  2  3  5  2  2  2  7  6  1  7  1  1  2  5  6  0  1  7  6  7  1  5  0  1  4  1  6  0  2  2  1  1  7  0  5  1  5  4
 0  0  1  0  2  5  7  1  1  3  4  6  0  7  7  2  1  1  0  5  6  0  5  4  1  1  4  5  6  6  1  1  2  1  1  5  3  5  7  1  4  1  7  6  1  7  2  5  1  3  5  0  5  0  5  1  6  6  3  7  0  6  0  4
 0  0  0  1  3  1  2  7  4  7  7  7  4  0  1  4  2  2  2  5  1  5  6  7  5  4  2  5  4  1  1  5  5  4  7  2  4  3  6  1  7  2  0  2  1  0  0  1  5  1  4  0  6  0  7  5  4  6  1  5  5  5  3  3
 0  0  0  0  4  0  4  4  0  4  4  0  4  4  0  0  0  4  0  4  4  0  0  0  4  4  0  0  4  0  0  4  4  0  0  4  0  4  0  4  4  4  4  0  0  0  4  0  0  4  4  0  4  4  4  0  4  0  0  0  4  0  0  4

generates a code of length 64 over Z8 who´s minimum homogenous weight is 57.

Homogenous weight enumerator: w(x)=1x^0+176x^57+344x^58+560x^59+633x^60+880x^61+561x^62+900x^63+606x^64+658x^65+601x^66+636x^67+439x^68+448x^69+253x^70+238x^71+97x^72+74x^73+31x^74+32x^75+16x^76+4x^77+2x^78+2x^79

The gray image is a code over GF(2) with n=256, k=13 and d=114.
This code was found by Heurico 1.16 in 2.04 seconds.