The generator matrix

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

generates a code of length 49 over GR(16,4) who´s minimum homogenous weight is 136.

Homogenous weight enumerator: w(x)=1x^0+435x^136+468x^137+312x^138+240x^139+1245x^140+864x^141+660x^142+372x^143+1641x^144+972x^145+816x^146+360x^147+1548x^148+1056x^149+648x^150+336x^151+1224x^152+780x^153+504x^154+168x^155+795x^156+384x^157+132x^158+60x^159+264x^160+84x^161+6x^164+3x^168+6x^172

The gray image is a code over GF(4) with n=196, k=7 and d=136.
This code was found by Heurico 1.16 in 0.841 seconds.