The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  2  1  2  1  2  1  2  1
 0  4  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  4  4  4  4  4  4  0  0  4  4  4  0
 0  0  4  0  0  0  0  0  0  0  0  0  4  0  0  4  4  4  4  4  4  0  4  4  4  4  0  0  0
 0  0  0  4  0  0  0  0  0  0  0  0  4  4  4  4  4  0  4  4  4  4  0  4  4  0  0  4  4
 0  0  0  0  4  0  0  0  0  0  0  4  0  4  4  0  4  4  4  0  4  0  0  4  0  4  0  4  4
 0  0  0  0  0  4  0  0  0  0  0  4  0  0  4  4  4  4  4  0  0  4  4  0  4  0  0  0  0
 0  0  0  0  0  0  4  0  0  0  4  0  0  0  4  4  0  0  4  0  4  0  4  4  4  0  4  0  0
 0  0  0  0  0  0  0  4  0  0  4  0  0  4  0  0  4  0  0  4  4  0  0  4  4  0  4  0  4
 0  0  0  0  0  0  0  0  4  0  4  4  4  4  0  0  0  0  4  0  4  4  0  0  4  4  0  4  4
 0  0  0  0  0  0  0  0  0  4  4  4  4  0  0  4  4  4  4  4  4  0  0  0  0  0  4  4  0

generates a code of length 29 over Z8 who´s minimum homogenous weight is 20.

Homogenous weight enumerator: w(x)=1x^0+116x^20+248x^24+160x^26+541x^28+2048x^29+320x^30+440x^32+32x^34+150x^36+30x^40+9x^44+1x^48

The gray image is a code over GF(2) with n=116, k=12 and d=40.
This code was found by Heurico 1.16 in 0.36 seconds.