*Article* **Appell-Type Functions and Chebyshev Polynomials**

#### **Pierpaolo Natalini 1 and Paolo Emilio Ricci 2,\***


Received: 13 June 2019; Accepted: 26 July 2019; Published: 30 July 2019

**Abstract:** In a recent article we noted that the first and second kind Cebyshev polynomials can be used to separate the real from the imaginary part of the Appell polynomials. The purpose of this article is to show that the same classic polynomials can also be used to separate the even part from the odd part of the Appell polynomials and of the Appell–Bessel functions.

**Keywords:** Bessel functions; Appell–Bessel functions; generating functions; Chebyshev polynomials

**MSC:** AMS 2010 Mathematics Subject Classifications: 33C99–11B83–12E10
