Divisibility by 2 and 3 of certain Stirling numbers
Number Theory
2008-07-17 v1 Algebraic Topology
Abstract
The numbers e_p(k,n) defined as min(nu_p(S(k,j)j!): j >= n) appear frequently in algebraic topology. Here S(k,j) is the Stirling number of the second kind, and nu_p(-) the exponent of p. The author and Sun proved that if L is sufficiently large, then e_p((p-1)p^L + n -1, n) >= n-1+nu_p([n/p]!). In this paper, we determine the set of integers n for which equality holds in this inequality when p=2 and 3. The condition is roughly that, in the base-p expansion of n, the sum of two consecutive digits must always be less than p.
Cite
@article{arxiv.0807.2629,
title = {Divisibility by 2 and 3 of certain Stirling numbers},
author = {Donald M Davis},
journal= {arXiv preprint arXiv:0807.2629},
year = {2008}
}
Comments
35 pages, submitted