The generator matrix

 1  1  1  1  1  1  1  1  1  7  1  1  1
 0  7  0  0  0  7  7 28  0  7  7  7 42
 0  0  7  0  0 35 28 35  7 42 14 21  0
 0  0  0  7  0 35 21 21 35 28  0 28 35
 0  0  0  0  7 35 42  7 42 35 28 28  7

generates a code of length 13 over Z49 who´s minimum homogenous weight is 56.

Homogenous weight enumerator: w(x)=1x^0+612x^56+1230x^63+2688x^70+14406x^72+5112x^77+86436x^79+4932x^84+2232x^91

The gray image is a code over GF(7) with n=91, k=6 and d=56.
This code was found by Heurico 1.16 in 1.52 seconds.