The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  1  1  1  1
 0  X  0  0  0  X  X  X a*X  0  X a*X a*X a*X a*X  0  X a^6*X a^4*X a^2*X  0
 0  0  X  0  0 a^6*X a^5*X a^4*X a^4*X  X a^3*X a^6*X  0  X a^5*X a*X a^3*X  0 a^4*X a^2*X  0
 0  0  0  X  0  X a^5*X a*X a^3*X a^2*X a^6*X  0 a^5*X  X a*X a^4*X a^3*X a^2*X a^3*X a^2*X  X
 0  0  0  0  X a^6*X a^3*X a*X a^5*X a*X a^2*X a^2*X a^3*X  0 a*X  X a^2*X a^4*X  0 a^5*X a^6*X

generates a code of length 21 over F8[X]/(X^2) who´s minimum homogenous weight is 112.

Homogenous weight enumerator: w(x)=1x^0+175x^112+1379x^120+2548x^128+4249x^136+28672x^140+7609x^144+200704x^148+9149x^152+5635x^160+2023x^168

The gray image is a linear code over GF(8) with n=168, k=6 and d=112.
This code was found by Heurico 1.16 in 9.27 seconds.