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A317760 Number of nX4 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
8, 20, 28, 43, 72, 127, 232, 432, 813, 1539, 2922, 5557, 10577, 20141, 38362, 73076, 139212, 265212, 505263, 962600, 1833903, 3493880, 6656412, 12681561, 24160471, 46029702, 87694221, 167072053, 318300013, 606414406, 1155320200, 2201076948 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A317764.

LINKS

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

FORMULA

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

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A317764.

Sequence in context: A207190 A110116 A295971 * A022757 A246308 A194218

Adjacent sequences:  A317757 A317758 A317759 * A317761 A317762 A317763

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 06 2018

STATUS

approved

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Last modified June 26 10:12 EDT 2019. Contains 324375 sequences. (Running on oeis4.)