The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X  0  0  X  X a*X a^3*X  0 2*X a^2*X  X a^2*X a*X a^2*X a^5*X 2*X a*X a*X  0
 0  0  X  0 a^7*X a^6*X a*X 2*X  X a^6*X a^6*X  X a^3*X  X a^5*X  X a^6*X a^5*X a^2*X a^5*X
 0  0  0  X a^7*X  X a^5*X a*X a*X a^7*X 2*X a^7*X a^3*X a^2*X 2*X a^3*X a^6*X a^2*X a^6*X 2*X

generates a code of length 20 over F9[X]/(X^2) who´s minimum homogenous weight is 135.

Homogenous weight enumerator: w(x)=1x^0+336x^135+1152x^144+1152x^153+52488x^160+1472x^162+1872x^171+576x^180

The gray image is a linear code over GF(9) with n=180, k=5 and d=135.
This code was found by Heurico 1.16 in 0.316 seconds.