A266207 Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any horizontal, vertical, diagonal or antidiagonal neighbor equal to n-1.
0, 0, 0, 8, 544, 20976, 3124800, 269723136, 61919980032, 9210279970560, 2897383466019840
Offset: 1
Keywords
Examples
Some solutions for n=6 ..0..2....2..0....2..1....0..2....2..1....2..4....5..3....5..4....1..2....3..0 ..1..1....2..4....0..0....0..1....2..0....0..2....4..3....3..5....0..0....4..4 ..3..0....0..4....4..4....1..3....4..4....4..0....4..0....3..1....4..2....2..5 ..3..4....3..3....3..3....3..5....5..5....3..3....2..0....0..1....5..4....2..5 ..4..5....5..5....5..5....4..5....3..1....5..1....2..1....0..2....3..3....1..1 ..2..5....1..1....2..1....2..4....0..3....1..5....5..1....2..4....5..1....0..3
Crossrefs
Cf. A266208.
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