The generator matrix

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

generates a code of length 21 over F8[X]/(X^2) who´s minimum homogenous weight is 126.

Homogenous weight enumerator: w(x)=1x^0+224x^126+553x^128+1792x^133+4704x^134+756x^136+3584x^140+25088x^141+32928x^142+756x^144+25088x^148+87808x^149+76832x^150+896x^152+882x^160+252x^168

The gray image is a linear code over GF(8) with n=168, k=6 and d=126.
This code was found by Heurico 1.16 in 20.8 seconds.