A303889 Number of n X n 0..1 arrays with every element unequal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

0, 7, 54, 1659, 29479, 1541443, 71307109, 5846922441, 668263785713, 103693982275562

Offset

1,2

Comments

Diagonal of A303896.

Links

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

Example

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

Crossrefs

Cf. A303896.

Sequence in context: A298104 A289865 A182124 * A198149 A203878 A043077

Adjacent sequences: A303886 A303887 A303888 * A303890 A303891 A303892

Keyword

nonn

Author

R. H. Hardin, May 02 2018

Status

approved