A320403 Number of nXn 0..1 arrays with every element unequal to 0, 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 6, 47, 786, 27236, 1957026, 282206549, 84346447443, 51065576746070, 63169593120391316

Offset

1,2

Comments

Diagonal of A320409.

Links

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

Example

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

Crossrefs

Cf. A320409.

Sequence in context: A353548 A192887 A321190 * A354067 A357430 A323138

Adjacent sequences: A320400 A320401 A320402 * A320404 A320405 A320406

Keyword

nonn

Author

R. H. Hardin, Oct 12 2018

Status

approved