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A317735 Number of nX2 0..1 arrays with every element unequal to 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 3
0, 1, 1, 2, 4, 9, 22, 53, 130, 320, 788, 1942, 4787, 11801, 29093, 71724, 176825, 435937, 1074742, 2649628, 6532293, 16104470, 39703357, 97883170, 241317504, 594935144, 1466730842, 3616023335, 8914808625, 21978235609, 54184319688, 133583994289 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Column 2 of A317741.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-3) -a(n-4) -a(n-5) -a(n-6)

EXAMPLE

All solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A317741.

Sequence in context: A129875 A055094 A055729 * A238826 A048211 A098719

Adjacent sequences:  A317732 A317733 A317734 * A317736 A317737 A317738

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 05 2018

STATUS

approved

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Last modified May 24 11:23 EDT 2019. Contains 323529 sequences. (Running on oeis4.)