login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 28 05:56 EST 2022. Contains 358407 sequences. (Running on oeis4.)