Formulas involving Cauchy polynomials, Bernoulli polynomials, and generalized Stirling numbers
José L. Cereceda
TL;DR
The paper develops a comprehensive framework linking Cauchy polynomials, both of the first and second kind, to generalized Stirling numbers, binomial coefficients, central factorial numbers, Euler and Bernoulli polynomials, r-Whitney numbers, and hyperharmonic polynomials. It derives explicit derivative formulas, inversion relations, and multiple representations, and extends these ideas to poly-Cauchy polynomials of order $k$ and a multiparameter poly-Cauchy framework with parameters $(a,q,L,y)$. Key contributions include new expressions of $c_n(x)$ and $\widehat{c}_n(x)$ in terms of generalized Stirling numbers, binomial bases, central factorial numbers, and Euler/Bernoulli polynomials; derivative formulas rooted in generalized Bernoulli polynomials; and a multiparameter theory that unifies shifted and $q$-parameter generalizations via bivariate Stirling polynomials and augmented polynomials. These results broaden the algebraic toolbox for Cauchy-type sequences and provide a rich set of identities for further exploration in combinatorial and number-theoretic contexts, with potential applications to poly-Bernoulli and hyperharmonic structures.
Abstract
In this paper, we derive novel formulas and identities connecting Cauchy numbers and polynomials with both ordinary and generalized Stirling numbers, binomial coefficients, central factorial numbers, Euler polynomials, $r$-Whitney numbers, and hyperharmonic polynomials, as well as Bernoulli numbers and polynomials. We also provide formulas for the higher-order derivatives of Cauchy polynomials and obtain corresponding formulas and identities for poly-Cauchy polynomials. Furthermore, we introduce a multiparameter framework for poly-Cauchy polynomials, unifying earlier generalizations like shifted poly-Cauchy numbers and polynomials with a $q$ parameter.
