A318030 Number of nXn 0..1 arrays with every element unequal to 0, 1, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 3, 9, 69, 580, 7728, 204645, 10928383, 1157058721, 226601121228

Offset

1,2

Comments

Diagonal of A318037.

Links

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

Example

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

Crossrefs

Cf. A318037.

Sequence in context: A119751 A276475 A084543 * A018564 A004167 A321539

Adjacent sequences: A318027 A318028 A318029 * A318031 A318032 A318033

Keyword

nonn

Author

R. H. Hardin, Aug 13 2018

Status

approved