Projection formulas for orthogonal polynomials
  We prove a projection formula for the four-parameter family of orthogonal polynomials that are a reparameterization of the polynomials in the Askey-Wilson class. By carefully analyzing the recurrence relations we manage to avoid using the explicit expression for the orthogonality measure, which would be cumbersome due to the complexity of the reparameterization. 
W. Bryc, W. Matysiak, R. Szwarc, J. Wesolowski