A304224 Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 7 king-move adjacent elements, with upper left element zero.

1, 4, 5, 11, 31, 306, 5541, 82029, 1842555, 145751601, 13209632311, 1320863549350, 329852488741611, 141595185654330078, 73958909238062935027

Offset

1,2

Comments

Diagonal of A304230.

Links

Table of n, a(n) for n=1..15.

Example

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

Crossrefs

Cf. A304230.

Sequence in context: A259821 A352681 A109503 * A304135 A251240 A361529

Adjacent sequences: A304221 A304222 A304223 * A304225 A304226 A304227

Keyword

nonn

Author

R. H. Hardin, May 08 2018

Status

approved