Counting non-isomorphic maximal independent sets of the \(n\)-cycle graph
Journal of integer sequences, Tome 11 (2008) no. 5
The number of maximal independent sets of the $n$-cycle graph $C_{n}$ is known to be 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 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 the Perrin and Padovan sequences.
Classification :
05C69, 05C38, 05A15, 05A17, 05C25
Keywords: maximal independent set, cycle graph, combinatorial enumeration, dihedral group, group action, cyclic and palindromic composition of integers, Perrin sequence, Padovan sequence
Keywords: maximal independent set, cycle graph, combinatorial enumeration, dihedral group, group action, cyclic and palindromic composition of integers, Perrin sequence, Padovan sequence
@article{JIS_2008__11_5_a4,
author = {Bisdorff, Raymond and Marichal, Jean-Luc},
title = {Counting non-isomorphic maximal independent sets of the \(n\)-cycle graph},
journal = {Journal of integer sequences},
year = {2008},
volume = {11},
number = {5},
zbl = {1165.05336},
language = {en},
url = {http://geodesic.mathdoc.fr/item/JIS_2008__11_5_a4/}
}
Bisdorff, Raymond; Marichal, Jean-Luc. Counting non-isomorphic maximal independent sets of the \(n\)-cycle graph. Journal of integer sequences, Tome 11 (2008) no. 5. http://geodesic.mathdoc.fr/item/JIS_2008__11_5_a4/