Some solutions for n=4
..x..0..x..1..x..2..x....x..0..x..1..x..2..x....x..0..x..1..x..2..x
..0..x..1..x..3..x..4....0..x..1..x..3..x..4....0..x..1..x..0..x..3
..x..2..x..5..x..4..x....x..2..x..0..x..5..x....x..2..x..4..x..5..x
..2..x..3..x..0..x..3....2..x..3..x..6..x..0....6..x..5..x..7..x..1
