The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  3  1  1  1
 0  3  0  0  0  0  0  0  0  3  3  0  0  6  3  3  0  3
 0  0  3  0  0  0  0  0  0  6  3  3  3  6  3  0  6  6
 0  0  0  3  0  0  0  0  3  6  0  6  6  0  3  0  6  6
 0  0  0  0  3  0  0  0  6  6  0  6  3  3  3  3  0  6
 0  0  0  0  0  3  0  0  6  6  3  6  0  6  0  6  0  6
 0  0  0  0  0  0  3  0  6  0  6  0  6  6  6  0  3  0
 0  0  0  0  0  0  0  3  6  0  3  3  6  3  0  6  6  6

generates a code of length 18 over Z9 who´s minimum homogenous weight is 21.

Homogenous weight enumerator: w(x)=1x^0+86x^21+248x^24+408x^27+678x^30+1104x^33+4374x^34+1350x^36+8748x^37+1176x^39+864x^42+426x^45+166x^48+52x^51+2x^54

The gray image is a code over GF(3) with n=54, k=9 and d=21.
This code was found by Heurico 1.16 in 0.942 seconds.