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

Author

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

Keywords

• easy
• nonn

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

• 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.

Crossrefs

Cf. A127682, A127683, A127685.

Formula

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