The generator matrix

 1  1  1  1  1  1
 0  7  0  7 21 21
 0  0  7 35 21 14

generates a code of length 6 over Z49 who´s minimum homogenous weight is 28.

Homogenous weight enumerator: w(x)=1x^0+90x^28+108x^35+2058x^36+144x^42

The gray image is a code over GF(7) with n=42, k=4 and d=28.
This code was found by Heurico 1.16 in 0.000313 seconds.