A297425 Number of n X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 neighboring 1's.

1, 2, 14, 42, 535, 11345, 431723, 28588498, 3362921639, 861591734557, 416496898515488, 327244273979649876, 483572529979247043390

Offset

1,2

Comments

Diagonal of A297431.

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=5
..0..0..1..1..0. .0..0..1..1..0. .0..1..1..0..0. .0..0..0..0..0
..0..1..0..0..1. .0..0..0..1..1. .0..1..1..0..0. .0..0..1..1..0
..1..0..0..1..0. .0..0..0..0..0. .0..0..0..0..0. .1..1..0..0..1
..0..1..1..0..0. .0..0..0..1..1. .0..0..0..1..1. .0..1..0..1..0
..0..0..0..0..0. .0..0..0..1..1. .0..0..0..1..1. .0..0..1..0..0

Crossrefs

Cf. A297431.

Sequence in context: A109137 A192375 A267247 * A108478 A262963 A195960

Adjacent sequences: A297422 A297423 A297424 * A297426 A297427 A297428

Keyword

nonn

Author

R. H. Hardin, Dec 30 2017

Status

approved