The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  X  0  1  1  1  1  1  1  1  1
 0  X  0  0  0  0  0  0  0  0  X  X  0  0  0  X  X  X  X  X  0  0  0  0  0  0  X  X
 0  0  X  0  0  0  0  0  0  X  X  X  0  X  X  0  X  X  0  0  0  0  0  0  X  X  X  X
 0  0  0  X  0  0  0  0  0  X  0  X  X  X  0  X  0  X  X  0  0  0  0  X  X  0  0  0
 0  0  0  0  X  0  0  0  X  0  0  X  X  0  X  X  0  0  X  X  0  0  X  X  0  0  0  0
 0  0  0  0  0  X  0  0  X  0  X  0  0  X  X  X  0  X  X  0  X  X  X  X  0  0  0  0
 0  0  0  0  0  0  X  0  X  X  X  0  0  0  X  X  X  0  0  X  X  X  0  X  0  X  0  0
 0  0  0  0  0  0  0  X  X  X  0  0  X  X  X  0  X  0  X  0  0  X  X  0  0  0  0  0

generates a code of length 28 over Z2[X]/(X^2) who´s minimum homogenous weight is 20.

Homogenous weight enumerator: w(x)=1x^0+29x^20+66x^24+128x^26+70x^28+128x^30+60x^32+25x^36+4x^44+1x^48

The gray image is a linear code over GF(2) with n=56, k=9 and d=20.
This code was found by Heurico 1.16 in 0.016 seconds.