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A303963 Number of nX2 0..1 arrays with every element unequal to 0, 1, 3 or 5 king-move adjacent elements, with upper left element zero. 8
2, 5, 9, 21, 53, 105, 237, 577, 1205, 2681, 6349, 13681, 30309, 70377, 154429, 342177, 783957, 1737881, 3857581, 8760529, 19527749, 43436873, 98090781, 219270657, 488654645, 1099633401, 2461435533, 5493590065, 12336038693, 27628989353 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A303969.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +8*a(n-3) -4*a(n-4)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303969.

Sequence in context: A117186 A155042 A001851 * A304349 A024822 A218966

Adjacent sequences:  A303960 A303961 A303962 * A303964 A303965 A303966

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 03 2018

STATUS

approved

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Last modified January 16 21:37 EST 2019. Contains 319206 sequences. (Running on oeis4.)