The generator matrix

 1  1  1  1  1  1  1
 0  X  0  0  0  X  X
 0  0  X  0  0 a^6*X a^5*X
 0  0  0  X  0  X a^5*X
 0  0  0  0  X a^6*X a^3*X

generates a code of length 7 over F8[X]/(X^2) who´s minimum homogenous weight is 24.

Homogenous weight enumerator: w(x)=1x^0+245x^24+1225x^32+5586x^40+12838x^48+229376x^49+12873x^56

The gray image is a linear code over GF(8) with n=56, k=6 and d=24.
This code was found by Heurico 1.16 in 0.787 seconds.