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A266009 Number of n X 5 integer arrays with each element equal to the number of horizontal and antidiagonal neighbors equal to itself. 1
1, 4, 11, 27, 70, 182, 483, 1281, 3389, 8986, 23818, 63151, 167404, 443816, 1176578, 3119246, 8269369, 21922921, 58119638, 154080691, 408482159, 1082924551, 2870933873, 7611114236, 20177774274, 53493165081, 141815376408, 375965811006 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - a(n-3) + 2*a(n-4) - 3*a(n-5) - a(n-6) for n>12.

Empirical g.f.: x*(1 + 2*x + x^2 - 2*x^3 - 4*x^4 - 6*x^5 - 3*x^6 + 4*x^7 - 5*x^8 + 2*x^9 - x^10 + x^11) / ((1 - x)*(1 + x^2)*(1 - x - 4*x^2 - x^3)). -  Colin Barker, Jan 09 2019

EXAMPLE

Some solutions for n=4:

..0..1..2..2..1....0..1..2..2..0....1..1..2..2..1....1..1..2..2..2

..1..2..2..1..0....1..2..2..1..1....0..2..2..1..0....0..2..0..2..2

..0..1..2..2..1....0..1..2..2..0....1..1..2..2..1....2..2..0..2..0

..1..2..2..1..0....1..2..2..1..1....0..2..2..1..0....2..2..2..1..1

CROSSREFS

Column 5 of A266012.

Sequence in context: A108985 A014151 A176759 * A096124 A269076 A282641

Adjacent sequences:  A266006 A266007 A266008 * A266010 A266011 A266012

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 20 2015

STATUS

approved

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Last modified September 22 03:20 EDT 2021. Contains 347605 sequences. (Running on oeis4.)