Some solutions for n=4
..0..0..1..1....0..1..1..2....0..1..2..3....0..1..2..3....0..0..1..1
..4..0..1..1....1..2..3..4....0..1..1..2....4..4..0..0....2..2..2..3
..2..2..3..4....2..3..4..4....4..4..0..1....1..2..3..4....4..0..0..1
..2..3..4..0....0..0..1..2....2..3..3..4....2..3..3..4....3..4..4..4
..2..3..3..4....3..3..4..0....2..3..4..0....0..1..1..2....1..2..3..3
|