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
 0  3  0  0  0  3  3  3 3a 6a+3  0  3 3a 6a+6 6a  6 6a+6  6 3a+6 6a 3a+3  0  0
 0  0  3  0  0 3a+6 6a+6 3a  6 3a+6  3 3a+6 3a 3a+3  3 3a+6  3 3a+3  6 3a  0  6  0
 0  0  0  3  0 3a+6  3 3a+3 3a+3 6a+6 6a+3 6a+6 6a+3 6a  3  3 6a  3 3a+3 3a+3  3  3 3a
 0  0  0  0  3 6a+6  6 6a+3  3  3 3a 3a  3 3a+3  0  6 6a 3a  3  0  6 3a+3  6

generates a code of length 23 over GR(81,9) who´s minimum homogenous weight is 144.

Homogenous weight enumerator: w(x)=1x^0+336x^144+2120x^153+4368x^162+7672x^171+13152x^180+472392x^184+16160x^189+11504x^198+3736x^207

The gray image is a code over GF(9) with n=207, k=6 and d=144.
This code was found by Heurico 1.16 in 27.5 seconds.