English

New results on the p-adic valuation of Stirling numbers

Number Theory 2021-11-18 v1

Abstract

We generalize results on the pp-adic valuations of S(n,k)S(n,k), the Stirling number of the second kind and s(n,k)s(n,k) the Stirling number of the first kind. We have several new estimates for these valuations, along with criteria for when the estimates are sharp. The primary foci are the explicit evaluation of ν2(S(n,k))\nu_2(S(n,k)) with n=c2hn=c2^h, k=b2h+ak=b2^h+a, a,b,c,h,k,nZ+a, b, c, h, k, n \in Z^+, and 1a2h11\le a \le 2^{h-1}, and νp(S(n,k))\nu_p(S(n,k)) when n=cphn=cp^h for an odd prime pp. We have strong new results, which generalize and strengthen previous results, for all primes. We also have some new results on the pp-adic valuations νp(s(n,k))\nu_p(s(n,k)) for all primes. We generally assume that p1nkp-1|n-k for exact values of νp(S(n,k))\nu_p(S(n,k)) or νp(s(n,k))\nu_p(s(n,k)). In addition, we have proved some new Amdeberhan-type identities for Stirling numbers of both kinds. We also extend some recent results and propose two new conjectures, as well as proofs and extensions of previous ones.

Keywords

Cite

@article{arxiv.2111.08766,
  title  = {New results on the p-adic valuation of Stirling numbers},
  author = {Arnold Adelberg and Tamas Lengyel},
  journal= {arXiv preprint arXiv:2111.08766},
  year   = {2021}
}