n16
1,2,3,4;
0,5,6,7;
0,5,8,9;
0,6,8,10;
0,7,9,10;
1,2,11,12;
1,3,11,13;
1,4,12,13;
2,3,11,14;
2,4,12,14;
3,4,13,14;
5,6,8,15;
5,7,9,15;
6,7,10,15;
8,9,10,15;
11,12,13,14.