Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.2......0.1......1.2......1.2......1.2......1.0......0.1......1.0
...3.4.0....2.0.3....0.1.1....0.3.4....2.2.2....2.3.2....0.0.1....0.1.2
..3.3.4.0..2.2.4.2..0.0.3.2..2.3.3.1..1.3.4.2..2.3.3.3..2.3.0.1..1.1.2.2