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A241364 Number of n X 2 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order. 1
1, 7, 47, 326, 2284, 16026, 112458, 789166, 5537942, 38862302, 272714782, 1913766030, 13429783278, 94243014094, 661346912462, 4640977825550, 32567892540814, 228543997497870, 1603799162836494, 11254602102332686 (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) = 7*a(n-1) + 2*a(n-3) - 8*a(n-4) for n>5.

Empirical g.f.: x*(1 + x)*(1 - x - x^2 - 4*x^3) / ((1 - x)*(1 - 6*x - 6*x^2 - 8*x^3)). - Colin Barker, Oct 30 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 2 of A241370.

Sequence in context: A244830 A126528 A214992 * A098405 A104092 A024187

Adjacent sequences: A241361 A241362 A241363 * A241365 A241366 A241367

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 20 2014

STATUS

approved

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Last modified January 31 22:24 EST 2023. Contains 359981 sequences. (Running on oeis4.)