A302723 Number of n X n 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 3, 22, 89, 1307, 20842, 532511, 17200486, 683140749, 61552556640

Offset

1,2

Comments

Diagonal of A302728.

Links

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

Example

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

Crossrefs

Cf. A302728.

Sequence in context: A368478 A277228 A302272 * A095663 A254332 A009029

Adjacent sequences: A302720 A302721 A302722 * A302724 A302725 A302726

Keyword

nonn

Author

R. H. Hardin, Apr 12 2018

Status

approved