The (r1,...,rp)-Bell polynomials
  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. 
Mohammed Said Maamra and Miloud Mihoubi
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