On the Wilf-Stanley limit of 4231-avoiding permutations and a conjecture of Arratia
Combinatorics
2012-05-16 v1
Abstract
We construct a sequence of finite automata that accept subclasses of the class of 4231-avoiding permutations. We thereby show that the Wilf-Stanley limit for the class of 4231-avoiding permutations is bounded below by 9.35. This bound shows that this class has the largest such limit among all classes of permutations avoiding a single permutation of length 4 and refutes the conjecture that the Wilf-Stanley limit of a class of permutations avoiding a single permutation of length k cannot exceed (k-1)^2.
Keywords
Cite
@article{arxiv.math/0502504,
title = {On the Wilf-Stanley limit of 4231-avoiding permutations and a conjecture of Arratia},
author = {M. H. Albert and M. Elder and A. Rechnitzer and P. Westcott and M. Zabrocki},
journal= {arXiv preprint arXiv:math/0502504},
year = {2012}
}
Comments
Submitted to Advances in Applied Mathematics