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URL: https://oeis.org/A296329

⇱ A296329 - OEIS

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A296329
Number of n X 2 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0 or 2 neighboring 1s.
2
3, 8, 19, 47, 116, 286, 705, 1738, 4285, 10564, 26044, 64208, 158296, 390257, 962125, 2371987, 5847808, 14416967, 35543051, 87626508, 216031114, 532595025, 1313039846, 3237119305, 7980672808, 19675252120, 48506630368, 119586431488
OFFSET
1,1
COMMENTS
Column 2 of A296335.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) + 3*a(n-3) + 2*a(n-4) + a(n-5).
Empirical g.f.: x*(3 + 5*x + 5*x^2 + 3*x^3 + x^4) / (1 - x - 2*x^2 - 3*x^3 - 2*x^4 - x^5). - Colin Barker, Mar 22 2018
EXAMPLE
Some solutions for n=5:
..1..0. .0..0. .1..0. .0..0. .1..0. .0..0. .1..0. .1..0. .0..0. .1..0
..0..0. .1..0. .0..0. .0..0. .0..1. .0..0. .0..0. .0..1. .0..1. .0..1
..0..0. .0..0. .0..0. .0..1. .0..0. .1..1. .1..0. .0..0. .0..0. .0..0
..0..1. .0..0. .0..0. .0..0. .0..1. .1..0. .0..0. .0..0. .0..0. .0..1
..1..1. .1..0. .0..1. .0..1. .0..0. .0..1. .0..0. .1..0. .1..0. .1..1
CROSSREFS
Cf. A296335.
Sequence in context: A121811 A370033 A244208 * A339525 A295045 A181849
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 10 2017
STATUS
approved