A304003 Number of n X n 0..1 arrays with every element unequal to 0, 2, 3 or 5 king-move adjacent elements, with upper left element zero.

1, 4, 13, 26, 137, 538, 4224, 30468, 264104, 2993696, 40315467

Offset

1,2

Comments

Diagonal of A304010.

Links

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

Example

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

Crossrefs

Cf. A304010.

Sequence in context: A049729 A189581 A206804 * A305356 A304946 A316616

Adjacent sequences: A304000 A304001 A304002 * A304004 A304005 A304006

Keyword

nonn

Author

R. H. Hardin, May 04 2018

Status

approved