The generator matrix

 1  1  1  1  1  1  1  X  1  X  X  1 X^2  0  X  1 X^2  1
 0 X^2  0 X^2  0 X^2  0 X^2 X^2  0 X^2  0 X^2 X^2  0 X^2  0  0

generates a code of length 18 over Z2[X]/(X^3) who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+1x^18+12x^19+1x^20+1x^22

The gray image is a linear code over GF(2) with n=72, k=4 and d=36.
This code was found by Heurico 1.16 in 0.00105 seconds.