A317808 - OEIS

A317808

Number of nXn 0..1 arrays with every element unequal to 0, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 2, 2, 7, 38, 142, 1575, 13712, 112854, 1446948, 21089268, 358570823, 7306257506

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OFFSET

1,2

COMMENTS

Diagonal of A317815.

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some solutions for n=5

..0..1..0..0..0. .0..1..0..0..1. .0..1..0..1..0. .0..1..0..0..0

..1..1..1..1..1. .1..1..1..1..0. .1..0..0..1..1. .1..1..1..1..1

..0..1..1..0..0. .0..1..1..0..0. .1..0..1..1..0. .0..1..1..0..0

..0..1..0..0..1. .0..1..0..0..0. .0..1..1..0..0. .0..1..0..0..1

..1..0..1..1..0. .1..0..0..0..0. .0..1..0..0..0. .0..1..0..1..0

CROSSREFS

Cf. A317815.

Sequence in context: A242032 A350019 A298440 * A326909 A343260 A246053

Adjacent sequences: A317805 A317806 A317807 * A317809 A317810 A317811

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 07 2018

STATUS

approved