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A304421 Number of nX2 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. 8
1, 7, 25, 98, 383, 1493, 5824, 22717, 88609, 345626, 1348139, 5258513, 20511208, 80005441, 312066973, 1217239658, 4747930775, 18519645245, 72237207376, 281766419413, 1099050170857, 4286924185562, 16721455908083, 65223240622649 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 2 of A304427.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +3*a(n-2) +2*a(n-3)
EXAMPLE
Some solutions for n=5
..0..1. .0..0. .0..1. .0..0. .0..1. .0..0. .0..1. .0..1. .0..1. .0..0
..0..1. .1..1. .0..0. .0..1. .1..1. .1..1. .1..1. .1..1. .0..1. .1..0
..0..0. .1..0. .1..1. .0..1. .0..1. .1..1. .0..1. .1..0. .1..1. .1..1
..0..1. .0..0. .0..1. .1..1. .0..0. .1..0. .1..1. .0..1. .0..1. .1..0
..1..1. .1..0. .1..1. .1..0. .0..1. .1..0. .0..1. .0..1. .0..1. .0..1
CROSSREFS
Cf. A304427.
Sequence in context: A261722 A256370 A199116 * A138729 A035509 A332942
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 12 2018
STATUS
approved

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Last modified February 22 09:46 EST 2024. Contains 370250 sequences. (Running on oeis4.)