About: Bessel polynomials

In mathematics, the Bessel polynomials are an orthogonal sequence of polynomials. There are a number of different but closely related definitions. The definition favored by mathematicians is given by the series Another definition, favored by electrical engineers, is sometimes known as the reverse Bessel polynomials The coefficients of the second definition are the same as the first but in reverse order. For example, the third-degree Bessel polynomial is while the third-degree reverse Bessel polynomial is The reverse Bessel polynomial is used in the design of Bessel electronic filters.