The generator matrix

 1  0  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1 2a+2 2a  2  1  1  1  1 2a  1 2a+2  1  1  1  1  0  1  1  1  1  1 2a 2a+2  1  1  0  1  1  2  1 2a+2  1  2  0  1  1  1  1  1
 0  1  0 2a+2 2a  2  1 3a+2 3a+3 2a+3 2a+1  3  a 3a 3a+1 a+1 a+2 a+3  1  1  1  0  1  a 3a+3  1 2a  1 a+3  2 2a+3 a+2  1  3 2a+1 2a+2 3a 3a+2  1  1 a+1 3a+1  1 3a+2 a+2  1  a  1  a  1  1 3a+1 a+3 3a+3 3a+1 a+1
 0  0  1  1  a 3a+3 3a+1 a+1 a+3 a+2 2a+1  2 2a+2  3 3a 2a+3 3a+2 2a 2a+1 3a a+1  2 3a+3  0 3a+1 3a+2 3a+2 a+3 2a+2 a+3  a a+2 3a+2 2a  1  3 2a+1 a+3 a+1  3 2a+1  a 2a 3a+2 2a+2  0  3  a a+3 a+3 2a+3 2a 3a+3  a  1  0

generates a code of length 56 over GR(16,4) who´s minimum homogenous weight is 161.

Homogenous weight enumerator: w(x)=1x^0+384x^161+516x^162+252x^163+9x^164+588x^165+528x^166+132x^167+27x^168+228x^169+312x^170+72x^171+21x^172+204x^173+144x^174+60x^175+252x^177+132x^178+36x^179+72x^181+96x^182+24x^183+6x^188

The gray image is a code over GF(4) with n=224, k=6 and d=161.
This code was found by Heurico 1.16 in 17.5 seconds.