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A127685 Number of non-isomorphic maximal independent sets of the n-cycle graph. 2
0, 1, 1, 1, 1, 2, 1, 2, 2, 3, 2, 4, 3, 5, 5, 7, 6, 10, 9, 14, 14, 20, 20, 30, 31, 44, 48, 67, 74, 104, 117, 161, 188, 254, 302, 407, 489, 654, 801, 1064, 1315, 1742, 2174, 2867, 3613, 4747, 6019, 7900, 10069, 13190, 16895, 22103, 28413, 37150, 47900, 62590, 80912 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

Number of non-isomorphic (i.e. defined up to a rotation and a reflection) maximal independent sets of the n-cycle graph. Also: Number of cyclic compositions of n in which each term is either 2 or 3, where a clockwise writing is not distinguished from its counterclockwise counterpart.

REFERENCES

R. Bisdorff and J.-L. Marichal, Counting non-isomorphic maximal independent sets of the n-cycle graph, ar2007.

LINKS

Table of n, a(n) for n=1..57.

R. Bisdorff and J.-L. Marichal, Counting non-isomorphic maximal independent sets of the n-cycle graph, arXiv:0701647 (2007) and JIS 11 (2008) 08.5.7.

FORMULA

a(n) = A127682(n) + Sum(d divides n) A127683(d) = (1/2)*(A127682(n) + (1/n)*(Sum(d divides n) A000010(n/d) A001608(d)))

CROSSREFS

Cf. A127682, A127683, A001608.

Sequence in context: A053267 A058768 A127682 * A127687 A024156 A241316

Adjacent sequences:  A127682 A127683 A127684 * A127686 A127687 A127688

KEYWORD

easy,nonn

AUTHOR

Jean-Luc Marichal (jean-luc.marichal(AT)uni.lu), Jan 24 2007

STATUS

approved

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Last modified July 8 04:16 EDT 2020. Contains 335504 sequences. (Running on oeis4.)