We show the classical q-Stirling numbers of the second kind can be expressed more compactly as a pair of statistics on a subset of restricted growth words. The resulting expressions are polynomials in q and 1+q. We extend this enumerative result via a decomposition of a new poset Π(n, k) which we call the Stirling poset of the second kind. Its rank generating function is the q-Stirling number S...

We prove an identity for sums of products of an arbitrary fixed number of Stirling numbers of the second kind; this can be seen as a generalized convolution identity. As a consequence we obtain two polynomial identities that also involve Stirling numbers of the second kind.

A Stirling number of the second kind is a combinatorial function which yields interesting number theoretic properties with regard to primality. The Stirling number of the second kind, S(n; k) = 1 k! k P i=0 ( 1) k i (k i), counts the number of partitions of an n-element set into k non-empty subsets. A Stirling prime (of the second kind) is a prime p such that p = S(n; k) for some integers n and...

The concept of Lucky k-polynomials and in particular Lucky χ-polynomials was recently introduced. This paper introduces Stirling number of the fourth kind and Lucky partitions of a finite set in order to determine either the Lucky k- or Lucky χ-polynomial of a graph. The integer partitions influence Stirling partitions of the second kind.

The Legendre-Stirling numbers are the coeffi cients in the integral Lagrangian symmetric powers of the classical Legendre second-order differential expression. In many ways, these numbers mimic the classical Stirling numbers of the second kind which play a similar role in the integral powers of the classical second-order Laguerre differential expression. In a recent paper, Andrews and Littlejoh...

Given positive integers n, k, and m, the (n, k)-th mrestrained Stirling number of the first kind is the number of permutations of an n-set with k disjoint cycles of length ≤ m. Inverting the matrix consisting of the (n, k)-th m-restrained Stirling number of the first kind as the (n+1, k +1)-th entry, the (n, k)-th m-restrained Stirling number of the second kind is defined. In this paper, the mu...