The generator matrix

 1  0  1  1  1  6  1  1 12  1  1 10  1  6  1  1  1  0  1 12  1 10  1  1 10  1  1  1  1  0  1  0  1  1  6  1  1  1  1 12  1  1  6  1 12  1  1 10  1  6  1  1  1  1  0 12  1  1  1 12  1  1  0  1 10  1  1 12  1  1  1  1  0  0  1  1  1  0  1  1
 0  1  3  6  5  1 12  7  1 10  9  1  6  1  3  0  5  1 12  1 15  1  9 10  1  5  0  3  6  1 10  1 12 15  1  9  0  5 10  1  3  6  1  5  1 12  9  1  6  1 15  0 10  0  1  1  9 15  6  1 10  3  1  9  1  3  9  1 10  5 15  3  1  1 11  3 10  1  3  3
 0  0  8  0  0  0  0  0  0  0  0  0  0  0  8  0  8  8  0  8  8  0  0  8  0  8  8  0  8  0  8  8  8  8  8  0  0  0  8  0  0  8  8  0  8  8  0  8  8  8  0  8  8  8  0  0  8  0  0  8  0  0  8  0  8  8  0  8  0  0  0  8  0  8  0  0  0  0  8  8
 0  0  0  8  0  0  0  0  0  0  0  0  8  0  0  0  0  8  8  8  0  8  0  0  8  0  8  8  0  8  8  0  8  0  8  0  8  8  0  0  8  8  0  8  8  8  8  0  8  0  8  8  8  8  0  8  0  0  0  8  0  8  8  0  8  0  8  8  8  0  8  8  0  8  8  8  0  0  8  0
 0  0  0  0  8  0  0  0  0  0  0  0  0  0  0  8  8  8  8  8  0  8  8  8  8  0  0  0  0  0  0  8  0  8  8  8  8  0  0  8  0  8  8  0  0  8  8  8  8  8  8  0  0  0  8  8  8  8  0  8  0  0  8  0  8  0  8  0  0  0  8  0  8  0  0  8  8  8  0  8
 0  0  0  0  0  8  0  0  0  0  0  0  0  8  0  8  0  0  8  8  8  8  0  8  0  0  8  8  8  8  8  8  0  0  0  0  8  0  8  0  0  0  0  0  0  8  0  8  8  0  8  0  8  0  8  0  8  8  8  0  0  0  8  8  0  0  0  8  0  0  8  8  8  0  8  0  8  8  8  8
 0  0  0  0  0  0  8  0  0  0  8  0  8  0  8  8  0  8  8  8  0  0  8  8  0  8  8  8  8  8  0  0  0  8  8  0  8  0  8  8  0  0  8  8  8  0  0  0  8  8  8  8  8  0  8  8  8  8  0  8  8  8  8  8  0  0  0  0  8  0  8  8  0  8  8  0  0  8  8  0
 0  0  0  0  0  0  0  8  0  0  0  8  0  8  8  8  0  8  8  0  0  0  8  0  8  0  0  8  0  8  0  0  8  8  8  0  0  8  0  8  8  0  0  0  0  0  8  0  0  0  8  0  8  0  8  8  8  8  8  0  8  8  0  0  0  8  8  0  8  8  0  0  0  8  0  8  0  8  0  0
 0  0  0  0  0  0  0  0  8  0  8  8  0  8  8  8  8  0  8  0  8  8  8  8  0  0  0  8  8  0  8  8  8  8  8  8  8  0  8  0  8  8  8  8  8  0  8  8  8  0  8  0  8  8  8  0  8  0  8  8  8  8  0  0  0  0  8  8  0  0  0  0  8  8  0  0  8  0  8  8
 0  0  0  0  0  0  0  0  0  8  8  0  8  0  8  8  0  8  8  8  8  8  0  0  8  0  0  0  0  8  8  0  0  0  8  8  0  0  8  0  8  8  8  0  8  0  0  8  0  0  0  0  8  0  8  8  8  0  0  0  0  8  0  8  0  0  8  0  0  8  8  8  8  0  8  0  0  0  8  0

generates a code of length 80 over Z16 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+115x^68+16x^69+108x^70+88x^71+558x^72+424x^73+1164x^74+1696x^75+3765x^76+4560x^77+7688x^78+7552x^79+10169x^80+7552x^81+7688x^82+4560x^83+3696x^84+1696x^85+1164x^86+424x^87+488x^88+88x^89+108x^90+16x^91+82x^92+41x^96+17x^100+6x^104+5x^108+1x^112

The gray image is a code over GF(2) with n=640, k=16 and d=272.
This code was found by Heurico 1.16 in 69.6 seconds.