A316731 Number of nXn 0..1 arrays with every element unequal to 0, 2, 3, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

1, 4, 5, 11, 55, 137, 275, 274113, 2083319, 5055566, 143371955631

Offset

1,2

Comments

Diagonal of A316733.

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Cf. A316733.

Sequence in context: A251240 A361529 A305041 * A253086 A260624 A067371

Adjacent sequences: A316728 A316729 A316730 * A316732 A316733 A316734

Keyword

nonn

Author

R. H. Hardin, Jul 11 2018

Status

approved