The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  1  2  1  1  1  1  1  1
 0  2  0  0  0  0  0  2  0  0  0  0  2  2  0  2  2  2  2  2  2  0  0  0
 0  0  2  0  0  0  0  2  0  0  2  2  2  2  2  0  0  2  0  2  0  0  0  2
 0  0  0  2  0  0  0  2  0  2  2  0  0  0  2  0  2  2  2  2  2  0  2  2
 0  0  0  0  2  0  0  2  0  2  0  2  0  2  2  2  0  0  0  2  2  2  2  2
 0  0  0  0  0  2  0  2  2  0  0  2  0  2  0  0  0  2  2  0  2  2  2  0
 0  0  0  0  0  0  2  2  2  0  2  0  0  2  2  2  0  0  2  2  0  0  2  0

generates a code of length 24 over Z4 who´s minimum homogenous weight is 20.

Homogenous weight enumerator: w(x)=1x^0+50x^20+32x^22+104x^24+32x^26+21x^28+15x^32+1x^44

The gray image is a code over GF(2) with n=48, k=8 and d=20.
This code was found by Heurico 1.16 in 1.44 seconds.