Rogers–Szegő polynomials
In mathematics, the Rogers–Szegő polynomials are a family of polynomials orthogonal on the unit circle introduced by Szegő (1926), who was inspired by the continuous q-Hermite polynomials studied by Leonard James Rogers. They are given by
where (q;q)n is the descending q-Pochhammer symbol.
Furthermore, the 
with 
