 Sieved ultraspherical polynomials

Sieved ultraspherical polynomials, more commonly referred to in the context of orthogonal polynomials, are a specific type of polynomial that arises from the study of special functions and approximation theory. To understand them better, it's useful to break down the terms: 1. **Ultraspherical Polynomials**: These are also known as Gegenbauer polynomials.