Wilf classification of bi-vincular permutation patterns
Combinatorics
2009-11-17 v2
Abstract
We classify all bi-vincular patterns of length two and three according to the number of permutations avoiding them. These patterns were recently defined by Bousquet-Melou et. al., and are natural generalizations of Babson and Steingrimsson's generalized patterns. The patterns are divided into seven and 24 Wilf classes, for lengths two and three, respectively. For most of the patterns an explicit form for the number of permutations avoiding the pattern is given.
Cite
@article{arxiv.0910.5103,
title = {Wilf classification of bi-vincular permutation patterns},
author = {Robert Parviainen},
journal= {arXiv preprint arXiv:0910.5103},
year = {2009}
}
Comments
Changed name of patterns to bi-vincular to confirm with new standard. Answered Question 2 and solved Conjecture 18. 16 pages, 4 figures