The generator matrix

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

generates a code of length 50 over GR(16,4) who´s minimum homogenous weight is 136.

Homogenous weight enumerator: w(x)=1x^0+567x^136+984x^137+564x^138+480x^139+2040x^140+2568x^141+1632x^142+1032x^143+3555x^144+3696x^145+2268x^146+1560x^147+4617x^148+5268x^149+2964x^150+2256x^151+5271x^152+5040x^153+2880x^154+1632x^155+4320x^156+4056x^157+1596x^158+648x^159+1920x^160+1320x^161+384x^162+72x^163+225x^164+108x^165+6x^168+6x^172

The gray image is a code over GF(4) with n=200, k=8 and d=136.
This code was found by Heurico 1.16 in 13.3 seconds.