The generator matrix

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

generates a code of length 20 over F8[X]/(X^2) who´s minimum homogenous weight is 120.

Homogenous weight enumerator: w(x)=1x^0+672x^120+560x^121+1792x^126+2744x^128+2800x^129+10752x^133+25088x^134+10332x^136+10640x^137+75264x^141+87808x^142+17822x^144+14672x^145+924x^152+273x^160

The gray image is a linear code over GF(8) with n=160, k=6 and d=120.
This code was found by Heurico 1.16 in 3.44 seconds.