Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.2......0.1......1.1......1.1......1.2......1.1......1.2......1.0
...1.2.2....2.2.1....0.1.0....0.0.2....3.3.3....0.1.0....1.0.0....0.2.2
..3.1.2.1..3.2.1.2..1.2.1.0..2.0.2.3..3.2.3.4..2.3.1.0..3.0.0.2..0.2.2.1
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