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A296968 Number of n X 2 0..1 arrays with each 1 adjacent to 2, 4 or 5 king-move neighboring 1s. 1
1, 5, 11, 21, 59, 145, 323, 793, 1939, 4561, 10939, 26425, 63107, 151057, 362923, 869609, 2083059, 4996033, 11977083, 28703897, 68813891, 164968369, 395429963, 947913481, 2272359443, 5447139489, 13057617307, 31301457785, 75034524387 (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) - a(n-2) + 6*a(n-3) - 4*a(n-4) + 2*a(n-5).

Empirical g.f.: x*(1 + 3*x + 2*x^2 - 2*x^3 + 2*x^4) / (1 - 2*x + x^2 - 6*x^3 + 4*x^4 - 2*x^5). - Colin Barker, Feb 25 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 2 of A296974.

Sequence in context: A234597 A261982 A296033 * A184552 A069097 A222548

Adjacent sequences:  A296965 A296966 A296967 * A296969 A296970 A296971

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 22 2017

STATUS

approved

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Last modified July 11 20:03 EDT 2020. Contains 335652 sequences. (Running on oeis4.)