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A127686 Number of non-isomorphic maximal independent sets of the n-cycle graph having no symmetry axis. 0
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 2, 2, 5, 4, 8, 9, 15, 16, 27, 30, 46, 55, 80, 96, 139, 168, 237, 293, 403, 503, 687, 864, 1164, 1477, 1974, 2516, 3348, 4282, 5668, 7284, 9604, 12374, 16279, 21022, 27597, 35718, 46819, 60693, 79480, 103174 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,19

COMMENTS

Number of non-isomorphic (i.e. defined up to a rotation and a reflection) maximal independent sets of the n-cycle graph having no symmetry axis. Also: Number of cyclic and non-palindromic compositions of n in which each term is either 2 or 3, where a clockwise writing is not distinguished from its counterclockwise counterpart.

LINKS

Table of n, a(n) for n=1..58.

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) = Sum(d divides n) A127683(d) = A127685(n) - A127682(n)

CROSSREFS

Cf. A127682, A127683, A127685.

Sequence in context: A089599 A206556 A127683 * A293548 A034400 A021820

Adjacent sequences:  A127683 A127684 A127685 * A127687 A127688 A127689

KEYWORD

easy,nonn

AUTHOR

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

STATUS

approved

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Last modified November 20 10:41 EST 2017. Contains 294963 sequences.