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A302304
Number of nX3 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
3, 11, 13, 33, 58, 153, 336, 937, 2449, 6560, 18488, 52053, 147896, 425764, 1229112, 3561761, 10353391, 30135225, 87835075, 256217794, 747737289, 2183170380, 6375689391, 18622164403, 54399493814, 158924553086, 464309179701
OFFSET
1,1
COMMENTS
Column 3 of A302309.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -2*a(n-2) +13*a(n-3) -23*a(n-4) +13*a(n-5) -42*a(n-6) +25*a(n-7) -21*a(n-8) -36*a(n-9) +48*a(n-10) -24*a(n-11) +8*a(n-12) +32*a(n-13) for n>16
EXAMPLE
Some solutions for n=5
..0..1..0. .0..1..0. .0..1..1. .0..1..0. .0..1..0. .0..0..1. .0..1..0
..1..1..0. .0..1..0. .1..0..1. .1..1..0. .0..1..0. .0..1..0. .1..1..0
..1..1..1. .0..1..0. .0..0..0. .0..1..0. .1..1..0. .1..1..1. .1..1..1
..1..1..0. .0..1..1. .0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..0
..0..1..0. .0..1..0. .1..0..1. .1..0..0. .0..0..0. .0..1..0. .1..0..0
CROSSREFS
Cf. A302309.
Sequence in context: A244047 A020451 A018450 * A119145 A168454 A181086
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 05 2018
STATUS
approved