The generator matrix

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

generates a code of length 51 over GR(16,4) who´s minimum homogenous weight is 140.

Homogenous weight enumerator: w(x)=1x^0+144x^140+12x^141+192x^144+144x^145+168x^148+648x^149+162x^152+1296x^153+63x^156+972x^157+75x^160+66x^164+33x^168+57x^172+18x^176+24x^180+15x^184+6x^188

The gray image is a code over GF(4) with n=204, k=6 and d=140.
This code was found by Heurico 1.16 in 0.239 seconds.