English

Sum rules for permutations with fixed points involving Stirling numbers of the first kind

Combinatorics 2026-03-10 v1

Abstract

We propose sum rules for permutations pn(k)p_n(k) of the ensemble {1,2,,n}\left\{1,2,\cdots,n\right\} with kk fixed points, in the form of partial sums of their moments. The corresponding identities involve Stirling numbers of the first kind s(q,r)s(q,r). Using a formula due to Vassilev-Missana and the Schl\"omlich expression of Stirling numbers, we also deduce sum rules for binomial coefficients. Connections with Bell numbers BnB_n are outlined.

Keywords

Cite

@article{arxiv.2603.07284,
  title  = {Sum rules for permutations with fixed points involving Stirling numbers of the first kind},
  author = {Jean-Christophe Pain},
  journal= {arXiv preprint arXiv:2603.07284},
  year   = {2026}
}

Comments

submitted to "Indonesian Journal of Combinatorics"