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A264952
Number of nX2 arrays containing 2 copies of 0..n-1 with no equal horizontal or vertical neighbors.
0
0, 2, 12, 504, 22320, 1521360, 140394240, 17034433920, 2627788262400, 502511002156800, 116684130094963200, 32342603041381248000
OFFSET
1,2
COMMENTS
Column 2 of A264954.
EXAMPLE
Some solutions for n=4
..1..2....2..0....2..3....2..1....3..1....0..3....1..2....3..2....0..1....3..1
..0..3....3..1....0..1....0..2....0..3....2..1....2..0....0..1....2..3....1..3
..3..1....0..2....1..3....3..0....2..0....1..3....0..3....2..3....1..0....2..0
..0..2....3..1....2..0....1..3....1..2....0..2....3..1....0..1....3..2....0..2
CROSSREFS
Cf. A264954.
Sequence in context: A013147 A250110 A266501 * A324790 A371202 A050643
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 29 2015
STATUS
approved