A304927 Number of n X n 0..1 arrays with every element unequal to 0, 1, 3, 5 or 7 king-move adjacent elements, with upper left element zero.

1, 5, 13, 73, 452, 2653, 15993, 118024, 920997, 12184613, 162877680, 2507024025, 36984184204, 682363665419

Offset

1,2

Comments

Diagonal of A304931.

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Cf. A304931.

Sequence in context: A137702 A140120 A303962 * A163732 A208821 A293259

Adjacent sequences: A304924 A304925 A304926 * A304928 A304929 A304930

Keyword

nonn

Author

R. H. Hardin, May 21 2018

Status

approved