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A282991 Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors. 1
7, 33, 163, 803, 3971, 19587, 96693, 477297, 2355925, 11629027, 57401721, 283338413, 1398577069, 6903468049, 34075967931, 168201202963, 830252119477, 4098178655825, 20228877377719, 99851059281979, 492871346862069 (list; graph; refs; listen; history; text; internal format)
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 * A295270 A275860 A054256

Adjacent sequences:  A282988 A282989 A282990 * A282992 A282993 A282994

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 26 2017

STATUS

approved

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Last modified August 10 03:47 EDT 2020. Contains 336368 sequences. (Running on oeis4.)