The generator matrix

 1  0  1  1  1  6  1  1  0  1  1  6  1  1  1  1  1  1  0  4
 0  1  3  6  5  1  0  3  1  6  5  1  4  6  2  3  7  0  1  1
 0  0  4  0  4  0  0  4  0  0  4  0  0  4  4  0  0  4  4  4
 0  0  0  4  4  4  4  4  4  0  0  0  4  4  0  0  4  4  4  0

generates a code of length 20 over Z8 who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+89x^18+76x^20+86x^22+1x^24+1x^26+2x^28

The gray image is a code over GF(2) with n=80, k=8 and d=36.
This code was found by Heurico 1.16 in 0.00414 seconds.