A302219 Number of n X 3 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 14, 43, 194, 675, 2666, 9819, 37382, 140039, 528962, 1989787, 7501790, 28252719, 106464314, 401084083, 1511229542, 5693728487, 21452605794, 80826937611, 304534567726, 1147401249247, 4323099142602, 16288258059235, 61369756239670

Offset: 1

Author

R. H. Hardin, Apr 03 2018

Keywords

• nonn

Comments

Column 3 of A302224.

Examples

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

Links

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

Crossrefs

Cf. A302224.

Formula

Empirical: a(n) = 3*a(n-1) +7*a(n-2) -5*a(n-3) -34*a(n-4) -46*a(n-5) +64*a(n-6) +112*a(n-7) +60*a(n-8) -96*a(n-9) -80*a(n-10) -64*a(n-11).