The generator matrix

 1  0  0  0  0  0  1  1  1  1
 0  1  0  0  0  0  1  0  0  X
 0  0  1  0  0  0  1  X  0  X
 0  0  0  1  0  0  1  X  0  0
 0  0  0  0  1  0  1  1  1 X+1
 0  0  0  0  0  1  1  1 X+1 X+1
 0  0  0  0  0  0  X  0  X  0

generates a code of length 10 over Z2[X]/(X^2) who´s minimum homogenous weight is 4.

Homogenous weight enumerator: w(x)=1x^0+95x^4+48x^5+373x^6+496x^7+953x^8+1504x^9+1261x^10+1504x^11+925x^12+496x^13+407x^14+48x^15+74x^16+7x^18

The gray image is a linear code over GF(2) with n=20, k=13 and d=4.
As d=4 is an upper bound for linear (20,13,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 13.
This code was found by Heurico 1.16 in 0.127 seconds.