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A303890 Number of nX2 0..1 arrays with every element unequal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero. 8
1, 7, 23, 86, 313, 1145, 4184, 15293, 55895, 204294, 746685, 2729101, 9974744, 36457249, 133249635, 487021534, 1780042209, 6505975697, 23779053976, 86911392597, 317657303391, 1161023421462, 4243489354069, 15509766267621 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A303896.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3) +4*a(n-4)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303896.

Sequence in context: A093069 A341665 A322269 * A003540 A063793 A217233

Adjacent sequences:  A303887 A303888 A303889 * A303891 A303892 A303893

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 02 2018

STATUS

approved

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Last modified August 10 20:05 EDT 2022. Contains 356039 sequences. (Running on oeis4.)