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A268907 Number of 4Xn 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1
0, 1344, 12960, 118584, 1004184, 8250912, 66210264, 522241560, 4063962024, 31282792704, 238663638432, 1807307152056, 13599932970888, 101786388133320, 758232651966984, 5625079743143376, 41579318178922608, 306353541215271960 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A268904.

LINKS

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

FORMULA

Empirical: a(n) = 18*a(n-1) -111*a(n-2) +282*a(n-3) -333*a(n-4) +180*a(n-5) -36*a(n-6) for n>12

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A268904.

Sequence in context: A259675 A205820 A202430 * A206321 A230974 A239192

Adjacent sequences:  A268904 A268905 A268906 * A268908 A268909 A268910

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 15 2016

STATUS

approved

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Last modified January 24 08:48 EST 2022. Contains 350534 sequences. (Running on oeis4.)