maximal independent set; cycle graph; combinatorial enumeration; dihedral group; group action; cyclic and palindromic composition of integers; Perrin and Padovan sequences
Résumé :
[en] The number of maximal independent sets of the n-cycle graph C_n is known to be the nth 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 unlabeled (i.e., defined up to a rotation) maximal independent sets and the number of unlabeled maximal independent sets having a given number of isomorphic representatives. It turns out that these formulas involve both Perrin and Padovan sequences.
Disciplines :
Mathématiques
Identifiants :
UNILU:UL-ARTICLE-2010-398
Auteur, co-auteur :
BISDORFF, Raymond ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Computer Science and Communications Research Unit (CSC)
MARICHAL, Jean-Luc ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Mathematics Research Unit
Langue du document :
Anglais
Titre :
Counting non-isomorphic maximal independent sets of the n-cycle graph