Some solutions for n=3
.......0............0............0............0............0............0
......0.2..........0.2..........0.2..........0.2..........0.2..........0.2
.....0.2.0........0.2.0........0.2.1........0.2.1........0.2.0........0.2.0
....2.0.3.0......0.1.2.0......0.2.1.0......0.2.0.1......2.0.2.0......0.3.0.2
...1.3.0.3.0....1.0.2.0.2....0.2.1.0.3....1.0.3.0.1....2.0.3.0.1....3.0.3.0.3
..1.3.2.0.3.0..1.0.2.0.2.0..1.0.2.0.2.3..2.0.3.1.0.2..2.1.0.3.0.1..3.0.2.3.0.3
|