Buchholz polynomials: A family of polynomials relating solutions of confluent hypergeometric and Bessel equations
\textit{H. Buchholz} [The confluent hypergeometric function with special emphasis on its applications (1969; Zbl 0169.08501), \S 7, Eq. (16)] gave a convergent expansion of the Whittaker function in a series of Bessel functions. Here this expansion is generalized to any solution of the confluent hypergeometric equation, by using a differential recurrence obeyed by the Buchholz polynomials.
scientific article; zbMATH DE number 1331093