A solution for n=3:
..0..0..0..0..1..1..1..1..1..1..1..1..0..0
..0..2..2..0..1..0..0..0..0..2..2..1..0..0
..0..2..2..0..1..0..2..2..0..2..2..1..2..2
..0..1..1..0..1..0..2..2..0..1..1..1..2..2
..0..1..1..0..1..0..0..0..0..1..2..2..1..1
..0..0..0..0..1..1..1..1..1..1..2..2..1..1
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