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A301786 Number of nX4 0..1 arrays with every element equal to 0 or 1 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
5, 9, 17, 32, 61, 116, 221, 421, 802, 1528, 2911, 5546, 10566, 20130, 38351, 73065, 139201, 265201, 505252, 962589, 1833892, 3493869, 6656401, 12681550, 24160460, 46029691, 87694210, 167072042, 318300002, 606414395, 1155320189, 2201076937 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A301790.

LINKS

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

FORMULA

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

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301790.

Sequence in context: A180565 A233187 A160426 * A258411 A059743 A000322

Adjacent sequences:  A301783 A301784 A301785 * A301787 A301788 A301789

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 26 2018

STATUS

approved

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Last modified August 19 18:30 EDT 2022. Contains 356229 sequences. (Running on oeis4.)