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A279851 Number of n X 2 0..2 arrays with no element unequal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
0, 4, 10, 24, 54, 116, 250, 528, 1118, 2348, 4930, 10312, 21542, 44900, 93450, 194176, 402926, 834972, 1728210, 3572920, 7378870, 15223764, 31379610, 64623344, 132974974, 273406476, 561726050, 1153278248, 2366208838, 4851722308 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + a(n-2) - 7*a(n-3) + 4*a(n-5).

Empirical g.f.: 2*x^2*(2 - x - 5*x^2) / ((1 - x)*(1 + x)^2*(1 - 2*x)^2). - Colin Barker, Feb 12 2019

EXAMPLE

Some solutions for n=4:

..0..1. .0..1. .0..0. .0..1. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0

..0..0. .0..1. .0..1. .0..0. .1..1. .0..0. .0..1. .1..0. .0..0. .1..0

..0..0. .1..1. .0..0. .0..0. .1..1. .0..0. .0..1. .0..0. .0..1. .1..0

..1..1. .1..1. .0..0. .2..2. .1..2. .0..1. .0..1. .0..0. .0..0. .1..0

CROSSREFS

Column 2 of A279856.

Sequence in context: A080615 A173729 A097976 * A266367 A316528 A152548

Adjacent sequences:  A279848 A279849 A279850 * A279852 A279853 A279854

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 20 2016

STATUS

approved

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Last modified October 18 12:18 EDT 2019. Contains 328160 sequences. (Running on oeis4.)