The generator matrix

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

generates a code of length 52 over GR(16,4) who´s minimum homogenous weight is 140.

Homogenous weight enumerator: w(x)=1x^0+231x^140+192x^141+60x^142+816x^143+1476x^144+1116x^145+228x^146+2388x^147+3057x^148+2352x^149+408x^150+3300x^151+4620x^152+2760x^153+696x^154+4956x^155+6066x^156+3552x^157+924x^158+5352x^159+5586x^160+3372x^161+612x^162+3612x^163+3495x^164+1680x^165+144x^166+996x^167+900x^168+336x^169+84x^171+78x^172+42x^176+24x^180+12x^184+9x^188+3x^192

The gray image is a code over GF(4) with n=208, k=8 and d=140.
This code was found by Heurico 1.16 in 14.6 seconds.