Pattern avoidance classes and subpermutations
Combinatorics
2007-05-23 v1
Abstract
Pattern avoidance classes of permutations that cannot be expressed as unions of proper subclasses can be described as the set of subpermutations of a single bijection. In the case that this bijection is a permutation of the natural numbers a structure theorem is given. The structure theorem shows that the class is almost closed under direct sums or has a rational generating function.
Cite
@article{arxiv.math/0402186,
title = {Pattern avoidance classes and subpermutations},
author = {M. D. Atkinson and M. M. Murphy and N. Ruskuc},
journal= {arXiv preprint arXiv:math/0402186},
year = {2007}
}
Comments
18 pages, 4 figures (all in-line)