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A183304 Half the number of nX3 binary arrays with no element equal to a strict majority of its horizontal and vertical neighbors 3
1, 4, 9, 19, 42, 93, 205, 452, 997, 2199, 4850, 10697, 23593, 52036, 114769, 253131, 558298, 1231365, 2715861, 5990020, 13211405, 29138671, 64267362, 141746129, 312630929, 689529220, 1520804569, 3354240067, 7398009354, 16316823277 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 3 of A183312
LINKS
FORMULA
Empirical: a(n)=2*a(n-1)+a(n-3).
Empirical G.f.: x*(1+x)^2/(1-2*x-x^3). [Colin Barker, Feb 23 2012]
EXAMPLE
Some solutions with a(1,1)=0 for 3X4
..0..1..0..1....0..0..1..1....0..1..0..1....0..1..0..0....0..1..1..0
..1..0..0..1....1..1..0..0....0..1..1..0....1..0..1..1....1..0..0..1
..0..1..1..0....0..1..0..1....1..0..1..0....0..1..0..0....0..1..1..0
CROSSREFS
Sequence in context: A300438 A034479 A326340 * A359278 A241351 A023377
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 03 2011
STATUS
approved

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Last modified February 25 19:10 EST 2024. Contains 370332 sequences. (Running on oeis4.)