The generator matrix

 1  0  0  1  1  1 10  4 12  1  1  1  1  1 10 14  1  1 12 10  1
 0  1  0  4  5  1  1  1 10  2 15  3  4  8  0  1 14  6  1  1  8
 0  0  1  7  3  4  3  2  1 12  8  5  1 14  1  6 10 12 11 13 12

generates a code of length 21 over Z16 who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+142x^18+640x^19+701x^20+1324x^21+496x^22+556x^23+171x^24+36x^25+18x^26+4x^27+7x^28

The gray image is a code over GF(2) with n=168, k=12 and d=72.
This code was found by Heurico 1.16 in 0.0419 seconds.