The generator matrix

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

generates a code of length 20 over Z49 who´s minimum homogenous weight is 91.

Homogenous weight enumerator: w(x)=1x^0+168x^91+936x^98+1584x^105+2616x^112+14406x^114+3816x^119+86436x^121+4428x^126+2520x^133+738x^140

The gray image is a code over GF(7) with n=140, k=6 and d=91.
This code was found by Heurico 1.16 in 3.14 seconds.