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A208317 Number of n X 3 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors. 1
5, 113, 2852, 71956, 1815496, 45806048, 1155714080, 29159359552, 735708134656, 18562357599488, 468339418067456, 11816484481570816, 298136992353470464, 7522175173859938304, 189788992300391874560, 4788490132956439724032 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A208322.

LINKS

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

FORMULA

Empirical: a(n) = 24*a(n-1) + 32*a(n-2) - 24*a(n-3) for n>4.

Empirical g.f.: x*(5 - 7*x - 20*x^2 + 12*x^3) / (1 - 24*x - 32*x^2 + 24*x^3). - Colin Barker, Jul 02 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Cf. A208322.

Sequence in context: A163014 A199650 A241109 * A279836 A279838 A009603

Adjacent sequences:  A208314 A208315 A208316 * A208318 A208319 A208320

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 25 2012

STATUS

approved

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Last modified January 19 20:48 EST 2022. Contains 350466 sequences. (Running on oeis4.)