A304265 Number of nX3 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.

3, 3, 6, 10, 19, 37, 67, 124, 235, 436, 808, 1513, 2821, 5245, 9784, 18247, 33982, 63334, 118075, 220021, 410023, 764248, 1424311, 2654380, 4947124, 9220057, 17183197, 32024569, 59684740, 111234331, 207308038, 386362258, 720065251, 1341989365

Offset: 1

Author

R. H. Hardin, May 09 2018

Keywords

• nonn

Comments

Column 3 of A304270.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A304270.

Formula

Empirical: a(n) = a(n-1) +3*a(n-3) for n>4