The generator matrix

 1  0  1  1  1  1  1  0  1  1  1  3  0
 0  1  1  8  0  7  8  1  0  7  8  3  1
 0  0  6  0  3  6  3  0  6  3  0  0  6
 0  0  0  3  3  6  6  3  0  0  6  6  0

generates a code of length 13 over Z9 who´s minimum homogenous weight is 21.

Homogenous weight enumerator: w(x)=1x^0+96x^21+214x^24+258x^27+154x^30+2x^33+2x^36+2x^39

The gray image is a code over GF(3) with n=39, k=6 and d=21.
This code was found by Heurico 1.16 in 0.00209 seconds.