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A127687
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Number of unlabeled maximal independent sets of the n-cycle graph.
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1
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0, 1, 1, 1, 1, 2, 1, 2, 2, 3, 2, 4, 3, 5, 6, 7, 7, 11, 11, 16, 19, 24, 28, 39, 46, 60, 75, 97, 120, 159, 197, 257, 327, 422, 539, 700, 892, 1157, 1488, 1928, 2479, 3219, 4148, 5383, 6961, 9029, 11687, 15184, 19673, 25564, 33174, 43125, 56010, 72868, 94719, 123283
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,6
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COMMENTS
| Number of unlabeled (i.e. defined up to a rotation) maximal independent sets of the n-cycle graph. Also: Number of cyclic compositions of n in which each term is either 2 or 3.
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REFERENCES
| R. Bisdorff and J.-L. Marichal, Counting non-isomorphic maximal independent sets of the n-cycle graph, preprint, 2007.
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LINKS
| R. Bisdorff and J.-L. Marichal, Counting non-isomorphic maximal independent sets of the n-cycle graph, preprint, 2007.
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FORMULA
| a(n) = Sum(d divides n) A113788(d) = 2 * A127685(n) - A127682(n) = (1/n)*(Sum(d divides n) A000010(n/d) A001608(d))
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CROSSREFS
| Cf. A127682, A127685, A113788, A001608.
Sequence in context: A058768 A127682 A127685 * A024156 A075989 A085432
Adjacent sequences: A127684 A127685 A127686 * A127688 A127689 A127690
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KEYWORD
| easy,nonn
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AUTHOR
| Jean-Luc Marichal (jean-luc.marichal(AT)uni.lu), Jan 24 2007
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