A305905 Number of nXn 0..1 arrays with every element unequal to 0, 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

1, 4, 35, 396, 15460, 595490, 42789430, 7157370110, 1710658272713, 714934693797269

Offset

1,2

Comments

Diagonal of A305911.

Links

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

Example

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

Crossrefs

Cf. A305911.

Sequence in context: A215541 A104456 A277868 * A324314 A123224 A160887

Adjacent sequences: A305902 A305903 A305904 * A305906 A305907 A305908

Keyword

nonn

Author

R. H. Hardin, Jun 14 2018

Status

approved