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A297296 Number of n X 5 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 2 neighboring 1s. 1
1, 4, 9, 21, 49, 114, 266, 620, 1446, 3372, 7864, 18340, 42772, 99752, 232640, 542560, 1265352, 2951040, 6882384, 16051024, 37434032, 87303264, 203607776, 474851968, 1107444896, 2582771648, 6023513600, 14047976768, 32762547648, 76408478336 (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) = 2*a(n-1) + 2*a(n-2) - 2*a(n-3) - 2*a(n-4) for n>5.

Empirical g.f.: x*(1 + x)*(1 + x - 2*x^2 - x^3) / (1 - 2*x - 2*x^2 + 2*x^3 + 2*x^4). - Colin Barker, Feb 26 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 5 of A297299.

Sequence in context: A084861 A122498 A132750 * A048582 A069231 A243635

Adjacent sequences:  A297293 A297294 A297295 * A297297 A297298 A297299

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 27 2017

STATUS

approved

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Last modified October 19 13:01 EDT 2019. Contains 328222 sequences. (Running on oeis4.)