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A297639 Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s. 1
8, 20, 113, 374, 1657, 6548, 28645, 119531, 517534, 2230834, 9747818, 42562432, 186902992, 822076283, 3625136416, 16002387208, 70728606718, 312843642490, 1384663445151, 6131158907181, 27157673366295, 120323002326873 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A297637.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) +a(n-2) -11*a(n-3) +26*a(n-4) -191*a(n-5) -121*a(n-6) +255*a(n-7) -69*a(n-8) +364*a(n-9) +346*a(n-10) -456*a(n-11) +189*a(n-12) -243*a(n-13) -20*a(n-14) -53*a(n-15) -33*a(n-16) -20*a(n-17) -4*a(n-18)

EXAMPLE

Some solutions for n=7

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

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

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

CROSSREFS

Cf. A297637.

Sequence in context: A014584 A074472 A175429 * A094253 A208084 A214905

Adjacent sequences:  A297636 A297637 A297638 * A297640 A297641 A297642

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 02 2018

STATUS

approved

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Last modified January 24 00:05 EST 2022. Contains 350515 sequences. (Running on oeis4.)