  We consider 3-parametric polynomials which replace the A-series interpolation
Macdonald polynomials in the BC case. For these polynomials, we prove: an
integral representation, a combinatorial formula, Pieri-type rules, Cauchy
identity, and we also show that they do not satisfy any rational q-difference
equation. We also prove a binomial formula for the 6-parametric Koornwinder
polynomials.
