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A297079 Number of n X 2 0..1 arrays with no 1 adjacent to 2 king-move neighboring 1s. 1
4, 12, 30, 96, 286, 848, 2620, 7964, 24332, 74740, 228968, 702656, 2157520, 6622672, 20336808, 62452688, 191784960, 588994592, 1808876976, 5555328528, 17061469024, 52399035584, 160927919584, 494243002176, 1517923151392, 4661861611200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 4*a(n-2) + 4*a(n-3) - 14*a(n-4) - 14*a(n-5) - 4*a(n-6).

Empirical g.f.: 2*x*(2 + 2*x - 5*x^2 - 14*x^3 - 9*x^4 - 2*x^5) / (1 - 2*x - 4*x^2 - 4*x^3 + 14*x^4 + 14*x^5 + 4*x^6). - Colin Barker, Feb 26 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 2 of A297085.

Sequence in context: A324943 A301875 A074252 * A074210 A299053 A005289

Adjacent sequences:  A297076 A297077 A297078 * A297080 A297081 A297082

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 2017

STATUS

approved

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Last modified July 13 13:48 EDT 2020. Contains 335688 sequences. (Running on oeis4.)