The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  0  X
 0  X 2X  0 X+3 2X X+3 2X+6  0  6  0  6 X+3 X+6  6 2X 2X+3 X+3  X  6  X  3  X 2X 2X+3 2X+3 2X+3 X+3 2X  X  0
 0  0  6  0  6  0  3  3  6  3  6  3  3  0  6  0  3  6  6  0  3  3  0  6  0  6  3  3  0  0  0
 0  0  0  6  3  6  6  3  3  6  0  3  3  3  6  3  6  0  6  3  0  0  6  3  0  6  0  3  0  6  0

generates a code of length 31 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 57.

Homogenous weight enumerator: w(x)=1x^0+132x^57+774x^60+1068x^63+102x^66+108x^69+2x^81

The gray image is a code over GF(3) with n=279, k=7 and d=171.
This code was found by Heurico 1.16 in 0.0214 seconds.