The generator matrix

 1  0  1  1  1  1
 0  1  1 31 16  0
 0  0 35  0 35  7
 0  0  0  7 28 28

generates a code of length 6 over Z49 who´s minimum homogenous weight is 21.

Homogenous weight enumerator: w(x)=1x^0+120x^21+294x^24+360x^28+8232x^30+3528x^31+972x^35+43218x^36+49392x^37+10584x^38+948x^42

The gray image is a code over GF(7) with n=42, k=6 and d=21.
This code was found by Heurico 1.16 in 0.115 seconds.