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, 72, 8536, 2231690, 1354321470, 2028744947006, 7685048253383394, 74968472049231105434, 1906199245553492643004970

Offset

1,3

Comments

Diagonal of A283100.

Links

Table of n, a(n) for n=1..10.

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

Adjacent sequences: A283090 A283091 A283092 * A283094 A283095 A283096

Keyword

nonn

Author

R. H. Hardin, Feb 28 2017

Status

approved