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A283093
Number of n X n 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors, with the exception of exactly two elements.
0
0, 0, 72, 8536, 2231690, 1354321470, 2028744947006, 7685048253383394, 74968472049231105434, 1906199245553492643004970
OFFSET
1,3
COMMENTS
Diagonal of A283100.
EXAMPLE
Some solutions for n=4
..0..0..1..0. .0..0..1..0. .0..1..0..0. .1..1..0..1. .1..0..0..1
..0..1..1..0. .1..0..1..0. .0..1..1..1. .1..0..0..1. .1..0..1..0
..0..0..1..1. .1..1..0..1. .1..0..0..0. .1..0..1..0. .1..1..0..0
..0..1..0..0. .0..0..1..1. .1..0..1..0. .0..1..0..1. .1..0..1..1
CROSSREFS
Cf. A283100.
Sequence in context: A289368 A334357 A119750 * A178635 A271189 A093272
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 28 2017
STATUS
approved