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A302219
Number of n X 3 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
1, 14, 43, 194, 675, 2666, 9819, 37382, 140039, 528962, 1989787, 7501790, 28252719, 106464314, 401084083, 1511229542, 5693728487, 21452605794, 80826937611, 304534567726, 1147401249247, 4323099142602, 16288258059235, 61369756239670
OFFSET
1,2
COMMENTS
Column 3 of A302224.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +7*a(n-2) -5*a(n-3) -34*a(n-4) -46*a(n-5) +64*a(n-6) +112*a(n-7) +60*a(n-8) -96*a(n-9) -80*a(n-10) -64*a(n-11).
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..1. .0..0..0
..1..1..0. .0..1..1. .1..1..0. .1..0..1. .1..1..1. .1..1..0. .0..1..1
..1..0..0. .1..0..1. .0..0..1. .1..1..0. .0..0..1. .0..1..1. .1..0..1
..1..0..0. .1..0..1. .0..1..1. .0..1..0. .1..0..0. .0..0..1. .1..0..0
..1..1..1. .0..1..1. .0..0..1. .1..0..0. .1..1..0. .1..1..0. .1..1..0
CROSSREFS
Cf. A302224.
Sequence in context: A242897 A120714 A041378 * A302665 A041380 A151990
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 03 2018
STATUS
approved