A282831 - OEIS

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A282831

Number of nX1 0..1 arrays with no 1 equal to more than one of its king-move neighbors, with the exception of exactly two elements.

0, 0, 0, 1, 2, 5, 13, 29, 65, 143, 307, 652, 1369, 2846, 5870, 12022, 24470, 49538, 99802, 200195, 400004, 796395, 1580451, 3127083, 6170303, 12144313, 23846197, 46721478, 91354371, 178285068, 347316524, 675472732, 1311610492, 2543054356, 4923747716

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

COMMENTS

Column 1 of A282838.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -2*a(n-3) -6*a(n-4) +4*a(n-6) +6*a(n-7) +3*a(n-8) +a(n-9).

Empirical: G.f.: x^4*(-1+x+x^2)/(x^3+x^2+x-1)^3 . - R. J. Mathar, Feb 23 2017

EXAMPLE

All solutions for n=6

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

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

..1. .1. .1. .1. .1

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

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

CROSSREFS

Cf. A282838.

Sequence in context: A091270 A376751 A214633 * A259762 A045703 A289843

Adjacent sequences: A282828 A282829 A282830 * A282832 A282833 A282834

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 22 2017

STATUS

approved