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A231257 Number of (n+1) X (2+1) 0..2 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..2 introduced in row major order. 1
3, 15, 89, 547, 3381, 20911, 129329, 799835, 4946509, 30591143, 189187465, 1170008467, 7235785189, 44748896799, 276744502881, 1711495152971, 10584548667901, 65458946997783, 404823472069561, 2503585087356803 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A231263.

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) -29*a(n-2) +36*a(n-3) -16*a(n-4).

Empirical g.f.: x*(1 - 2*x)*(3 - 9*x + 8*x^2) / ((1 - x)*(1 - 9*x + 20*x^2 - 16*x^3)). - Colin Barker, Feb 16 2018

EXAMPLE

Some solutions for n=3:

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

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

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

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

CROSSREFS

Sequence in context: A192253 A127785 A287511 * A074541 A074550 A205576

Adjacent sequences:  A231254 A231255 A231256 * A231258 A231259 A231260

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 06 2013

STATUS

approved

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Last modified July 25 03:53 EDT 2021. Contains 346283 sequences. (Running on oeis4.)