Alternating runs of permutations and the central factorial numbers
Combinatorics
2022-03-07 v3
Abstract
Let R(n,k) be the number of permutations of with k alternating runs. In this paper, we establish the relationships between R(n,k) and the central factorial numbers of even indices as well as the number of signed permutations with a given number of alternating runs and the central factorial numbers of odd indices. The explicit formulas of the peak and left peak polynomials for permutations and the derivative polynomials of the tangent and secant functions are also established.
Keywords
Cite
@article{arxiv.2202.13978,
title = {Alternating runs of permutations and the central factorial numbers},
author = {Qi Fang and Ya-Nan Feng and Shi-Mei Ma},
journal= {arXiv preprint arXiv:2202.13978},
year = {2022}
}
Comments
10 pages