maximal independent set; cycle graph; combinatorial enumeration; dihedral group; group action; cyclic and palindromic composition of integers; Perrin and Padovan sequences
Abstract :
[en] It is known that the number of maximal independent sets of the $n$-cycle graph $C_n$ is given by the $n$th term of the Perrin sequence. The action of the automorphism group of $C_n$ on the family of these maximal independent sets partitions this family into disjoint orbits, which represent the non-isomorphic (i.e., defined up to a rotation and a reflection) maximal independent sets. We provide exact formulas for the total number of orbits and the number of orbits having a given number of isomorphic representatives. We also provide exact formulas for the total number of unlabelled (i.e., defined up to a rotation) maximal independent sets and the number of unlabelled maximal independent sets having a given number of isomorphic representatives. It turns out that these formulas involve both Perrin and Padovan sequences.
Disciplines :
Mathematics
Author, co-author :
BISDORFF, Raymond ; University of Luxembourg > Faculty of Law, Economics and Finance > Applied Mathematics Unit (SMA)
MARICHAL, Jean-Luc ; University of Luxembourg > Faculty of Law, Economics and Finance > Applied Mathematics Unit (SMA)
External co-authors :
no
Language :
English
Title :
Counting non-isomorphic maximal independent sets of the n-cycle graph
Publication date :
January 2007
Number of pages :
1
Event name :
21st Annual Conf. of the Belgian Operational Research Society (ORBEL 21), Luxembourg, Jan. 18-19, 2007
Event organizer :
Raymond Bisdorff Claude Lamboray Jean-Luc Marichal Patrick Meyer