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