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A318018 Number of nX2 0..1 arrays with every element unequal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 2
2, 6, 14, 35, 95, 257, 700, 1907, 5202, 14190, 38712, 105614, 288137, 786105, 2144674, 5851173, 15963362, 43551783, 118819435, 324167181, 884403808, 2412860224, 6582846451, 17959543175, 48997829987, 133677528403, 364703530888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A318024.

LINKS

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

FORMULA

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

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A318024.

Sequence in context: A178320 A297187 A231509 * A025257 A283438 A323027

Adjacent sequences:  A318015 A318016 A318017 * A318019 A318020 A318021

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 12 2018

STATUS

approved

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Last modified April 11 10:52 EDT 2021. Contains 342886 sequences. (Running on oeis4.)