Plethystic Exponential Polynomials and Plethystic Stirling Numbers

In this article we introduce a plethystic generalization of the exponential polynomials and their umbral inverses. We obtain recursive formulas for both families of polynomials, and use them to get recursions for the plethystic Stirling numbers of the first and second kind and for the plethystic Bell numbers. Finally, we apply Bergeron's S‐species to obtain a Dobinsky formula for the plethystic exponential polynomials and a close formula for the plethystic Stirling numbers of the second kind.