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A280437 Number of n X 5 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
5, 38, 77, 138, 225, 360, 574, 920, 1487, 2422, 3971, 6542, 10814, 17914, 29713, 49314, 81861, 135876, 225470, 373996, 620083, 1027598, 1702087, 2817898, 4662910, 7712270, 12749909, 21068730, 34800297, 57457632, 94828606, 156445952 (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) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>7.

Empirical g.f.: x*(5 + 18*x - 55*x^2 - 8*x^3 + 37*x^4 + 14*x^5 + 7*x^6) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 13 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 5 of A280440.

Sequence in context: A061674 A247709 A097276 * A222646 A145156 A318102

Adjacent sequences:  A280434 A280435 A280436 * A280438 A280439 A280440

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 03 2017

STATUS

approved

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Last modified September 24 10:48 EDT 2021. Contains 347642 sequences. (Running on oeis4.)