The generator matrix

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

generates a code of length 55 over GR(16,4) who´s minimum homogenous weight is 156.

Homogenous weight enumerator: w(x)=1x^0+210x^156+156x^157+264x^159+678x^160+144x^161+264x^163+636x^164+216x^165+48x^167+480x^168+96x^169+396x^172+108x^173+168x^175+150x^176+48x^177+24x^179+6x^188+3x^192

The gray image is a code over GF(4) with n=220, k=6 and d=156.
This code was found by Heurico 1.16 in 0.0925 seconds.