Some solutions for 4X4
..0..1..1..2....0..1..0..2....0..1..2..1....0..1..0..4....0..1..0..2
..1..0..1..4....1..0..1..0....1..0..2..0....1..0..1..0....1..0..1..3
..1..1..1..0....1..1..0..3....1..2..3..1....4..1..4..3....0..1..1..2
..2..4..0..1....3..1..3..1....2..2..4..3....4..0..3..1....2..1..0..3
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