The generator matrix

 1  1  1  1  1  1  1  1
 0  X  0  X 3X 6X 6X 4X
 0  0  X 5X 3X  X 3X 5X

generates a code of length 8 over Z7[X]/(X^2) who´s minimum homogenous weight is 42.

Homogenous weight enumerator: w(x)=1x^0+168x^42+2058x^48+48x^49+126x^56

The gray image is a linear code over GF(7) with n=56, k=4 and d=42.
This code was found by Heurico 1.16 in 0.00041 seconds.