Some solutions for n=3
..0..4..0....0..4..0....0..4..0....0..4..0....0..4..0....0..4..0....0..4..0
..0..4..0....0..4..0....0..4..0....0..4..0....0..4..0....0..4..0....0..4..0
..0..2..6....0..2..6....0..4..0....0..4..6....0..2..6....0..4..6....0..2..0
..6..4..0....3..7..5....0..2..0....6..4..0....6..7..5....6..2..6....6..2..0
..0..1..0....3..1..0....0..1..3....6..2..0....5..4..0....3..2..6....6..2..6
..5..4..5....0..2..0....0..2..0....6..4..6....0..2..3....0..2..6....0..4..0
Vertex neighbors:
0 -> 1 2 4
1 -> 0 3 5
2 -> 0 3 6
3 -> 1 2 7
4 -> 0 5 6
5 -> 1 4 7
6 -> 2 4 7
7 -> 3 5 6
|