A282991 Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors.

7, 33, 163, 803, 3971, 19587, 96693, 477297, 2355925, 11629027, 57401721, 283338413, 1398577069, 6903468049, 34075967931, 168201202963, 830252119477, 4098178655825, 20228877377719, 99851059281979, 492871346862069

Offset: 1

Author

R. H. Hardin, Feb 26 2017

Keywords

• nonn

Comments

Column 3 of A282996.

Examples

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

Links

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

Crossrefs

Cf. A282996.

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) +20*a(n-3) +13*a(n-4) -9*a(n-5) -10*a(n-6) -3*a(n-7) -a(n-8) +a(n-9).

Empirical: G.f.: -x*(7+19*x+27*x^2+7*x^3-16*x^4-11*x^5-3*x^6+x^8) / ( (1+x)*(x^8-2*x^7-x^6-9*x^5+13*x^3+7*x^2+3*x-1) ). - R. J. Mathar, Mar 02 2017