The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  4  0  0  0  0  0  0  0  0  0  0  0  4  4  4  0  0
 0  0  4  0  0  0  0  0  0  0  0  0  4  4  4  0  0  0
 0  0  0  4  0  0  0  0  0  0  0  0  4  0  4  4  0  0
 0  0  0  0  4  0  0  0  0  0  0  0  4  4  0  4  0  0
 0  0  0  0  0  4  0  0  0  0  0  4  4  4  4  4  0  0
 0  0  0  0  0  0  4  0  0  0  0  4  0  0  4  4  0  0
 0  0  0  0  0  0  0  4  0  0  0  4  0  4  4  0  0  0
 0  0  0  0  0  0  0  0  4  0  0  4  0  4  0  4  0  0
 0  0  0  0  0  0  0  0  0  4  0  4  4  0  0  4  0  0
 0  0  0  0  0  0  0  0  0  0  4  4  4  0  4  0  0  0

generates a code of length 18 over Z8 who´s minimum homogenous weight is 8.

Homogenous weight enumerator: w(x)=1x^0+105x^8+315x^12+603x^16+6144x^18+603x^20+315x^24+105x^28+1x^36

The gray image is a code over GF(2) with n=72, k=13 and d=16.
This code was found by Heurico 1.16 in 0.176 seconds.