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A297452 Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0 or 2 neighboring 1s. 1
5, 25, 92, 390, 1652, 6888, 28971, 121854, 512165, 2153841, 9057847, 38091340, 160192797, 673691652, 2833214557, 11915133080, 50109322975, 210735765317, 886253689076, 3727158731899, 15674645707885, 65920058839981 (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) = 5*a(n-1) - 3*a(n-2) + 4*a(n-3) - 25*a(n-4) + 10*a(n-5) - 7*a(n-6) + 12*a(n-7).

Empirical g.f.: x*(5 - 18*x^2 - 15*x^3 + 3*x^4 + 5*x^5 + 12*x^6) / (1 - 5*x + 3*x^2 - 4*x^3 + 25*x^4 - 10*x^5 + 7*x^6 - 12*x^7). - Colin Barker, Feb 28 2019

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Column 3 of A297457.

Sequence in context: A083090 A224148 A265929 * A147177 A057255 A134140

Adjacent sequences:  A297449 A297450 A297451 * A297453 A297454 A297455

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 30 2017

STATUS

approved

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Last modified January 19 04:56 EST 2022. Contains 350464 sequences. (Running on oeis4.)