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A297909 Number of n X 2 0..1 arrays with every element equal to 0, 2, 3 or 4 king-move adjacent elements, with upper left element zero. 5
1, 5, 12, 37, 104, 301, 864, 2485, 7144, 20541, 59056, 169797, 488184, 1403597, 4035520, 11602645, 33359112, 95911773, 275758800, 792842341, 2279524632, 6553929197, 18843397088, 54177212405, 155766517544, 447848955517 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A297915.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-2) + 8*a(n-3) + 4*a(n-4).

Empirical g.f.: x*(1 + 5*x + 7*x^2 + 4*x^3) / ((1 + x)*(1 - x - 4*x^2 - 4*x^3)). - Colin Barker, Feb 21 2018

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Cf. A297915.

Sequence in context: A301873 A077918 A300534 * A220705 A034752 A095310

Adjacent sequences:  A297906 A297907 A297908 * A297910 A297911 A297912

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 08 2018

STATUS

approved

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Last modified September 28 04:28 EDT 2022. Contains 357063 sequences. (Running on oeis4.)