Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.2......0.1......0.0......0.0......1.2......1.1......0.0......1.2
...3.1.2....2.3.2....1.2.3....1.1.2....0.3.0....2.1.2....1.2.3....2.0.1
..4.1.2.2..1.0.2.2..4.4.4.2..0.0.0.0..0.4.0.0..1.2.2.3..1.4.2.3..2.0.1.1
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