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

generates a code of length 70 over GR(16,4) who´s minimum homogenous weight is 204.

Homogenous weight enumerator: w(x)=1x^0+1353x^204+1452x^208+285x^212+855x^220+147x^224+3x^228

The gray image is a code over GF(4) with n=280, k=6 and d=204.
This code was found by Heurico 1.16 in 98.3 seconds.