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A232290 Number of n X 3 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally. 1
7, 97, 1313, 17759, 240241, 3249889, 43963319, 594719777, 8045152705, 108831897871, 1472238306545, 19915904010305, 269415101335399, 3644549440989793, 49302138454678241, 666941386187953343 (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) + 20*a(n-2) + 9*a(n-3).

Empirical g.f.: x*(7 + 13*x + 9*x^2) / (1 - 12*x - 20*x^2 - 9*x^3). - Colin Barker, Oct 04 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 3 of A232295.

Sequence in context: A074110 A155644 A243867 * A011943 A218669 A188441

Adjacent sequences:  A232287 A232288 A232289 * A232291 A232292 A232293

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 22 2013

STATUS

approved

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Last modified May 26 00:32 EDT 2020. Contains 334613 sequences. (Running on oeis4.)