The generator matrix

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

generates a code of length 23 over Z2[X]/(X^2) who�s minimum homogenous weight is 24.

Homogenous weight enumerator: w(x)=1x^0+13x^24+2x^28

The gray image is a linear code over GF(2) with n=46, k=4 and d=24.
As d=24 is an upper bound for linear (46,4,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 4.
This code was found by Heurico 1.16 in 0.00136 seconds.