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A269007 Number of n X 4 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once. 1
5, 36, 305, 2136, 14240, 91048, 566656, 3456320, 20760192, 123186784, 723791744, 4218132480, 24414483712, 140486492800, 804321836032, 4584741088256, 26032741150720, 147311358346752, 831044097026048, 4675403505475584 (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) = 12*a(n-1) - 40*a(n-2) + 8*a(n-3) + 92*a(n-4) - 32*a(n-5) - 64*a(n-6) for n>7.

Empirical g.f.: x*(5 - 24*x + 73*x^2 - 124*x^3 + 60*x^4 + 16*x^5 + 4*x^6) / (1 - 6*x + 2*x^2 + 8*x^3)^2. - Colin Barker, Jan 18 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 4 of A269011.

Sequence in context: A255489 A091161 A135149 * A246510 A278576 A286765

Adjacent sequences:  A269004 A269005 A269006 * A269008 A269009 A269010

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 17 2016

STATUS

approved

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Last modified August 7 22:44 EDT 2020. Contains 336279 sequences. (Running on oeis4.)