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, 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

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 A318844 A034400

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