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

1,1

Comments

Column 3 of A282996.

Links

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

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

Example

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

Crossrefs

Cf. A282996.

Sequence in context: A227555 A304278 A155603 * A344816 A295270 A275860

Adjacent sequences: A282988 A282989 A282990 * A282992 A282993 A282994

Keyword

nonn

Author

R. H. Hardin, Feb 26 2017

Status

approved