The generator matrix

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

generates a code of length 5 over Z2[X]/(X^3) who´s minimum homogenous weight is 2.

Homogenous weight enumerator: w(x)=1x^0+15x^2+12x^3+16x^4+168x^5+16x^6+12x^7+15x^8+1x^10

The gray image is a linear code over GF(2) with n=20, k=8 and d=4.
This code was found by Heurico 1.16 in 9.61e-005 seconds.