A297727 Number of n X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 4 neighboring 1's.

1, 2, 17, 93, 2719, 65215, 6241242, 959915987, 322119198752, 199728169017008

Offset

1,2

Comments

Diagonal of A297733.

Links

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

Example

Some solutions for n=6
..0..0..1..1..1..0. .0..0..1..0..1..0. .1..1..0..1..1..1. .0..1..1..0..0..0
..1..1..0..0..0..1. .0..1..1..1..0..1. .1..1..0..0..1..0. .1..0..0..1..1..1
..1..1..1..0..1..1. .0..0..0..0..1..0. .0..0..0..1..0..1. .0..1..1..0..1..0
..1..0..0..0..1..0. .1..1..0..1..0..1. .1..1..0..0..1..0. .1..1..1..1..0..1
..0..1..1..0..0..1. .1..1..0..0..1..1. .1..1..0..1..0..1. .1..0..0..1..1..1
..0..0..0..1..1..0. .0..0..0..0..1..1. .0..0..0..0..1..0. .0..1..1..0..1..0

Crossrefs

Cf. A297733.

Sequence in context: A081744 A372189 A219757 * A358591 A002645 A100268

Adjacent sequences: A297724 A297725 A297726 * A297728 A297729 A297730

Keyword

nonn

Author

R. H. Hardin, Jan 04 2018

Status

approved