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A304265
Number of nX3 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.
1
3, 3, 6, 10, 19, 37, 67, 124, 235, 436, 808, 1513, 2821, 5245, 9784, 18247, 33982, 63334, 118075, 220021, 410023, 764248, 1424311, 2654380, 4947124, 9220057, 17183197, 32024569, 59684740, 111234331, 207308038, 386362258, 720065251, 1341989365
OFFSET
1,1
COMMENTS
Column 3 of A304270.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-3) for n>4
EXAMPLE
Some solutions for n=5
..0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0
..1..0..0. .0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .1..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..1
..0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
CROSSREFS
Cf. A304270.
Sequence in context: A300301 A031504 A298164 * A049871 A049924 A049926
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 09 2018
STATUS
approved