The (r1,...,rp)-Bell polynomials

Abstract

In a previous paper, Mihoubi et al. introduced the $(r_{1},...,r_{p}) $-Stirling numbers and the $(r_{1},...,r_{p}) $-Bell polynomials and gave some of their combinatorial and algebraic properties. These numbers and polynomials generalize, respectively, the $r$-Stirling numbers of the second kind introduced by Broder and the $r$-Bell polynomials introduced by Mez\H{o}. In this paper, we prove that the $(r_{1},...,r_{p}) $-Stirling numbers of the second kind are log-concave. We also give generating functions and generalized recurrences related to the $(r_{1},...,r_{p}) $-Bell polynomials.