Some transformation formulas associated with Askey-Wilson polynomials   and Lassalle's formulas for Macdonald-Koornwinder polynomials
  We present a fourfold series expansion representing the Askey-Wilson polynomials. To obtain the result, a sequential use is made of several summation and transformation formulas for the basic hypergeometric series, including the Verma's q-extension of the Field and Wimp expansion, Andrews' terminating q-analogue of Watson's 3F2 sum, Singh's quadratic transformation. As an application, we present an explicit formula for the Koornwinder polynomial of type BCn (n in Z_>0) with one row diagram. When the parameters are specialized, we recover Lassalle's formula for Macdonald polynomials of type Bn, Cn and Dn with one row diagram, thereby proving his conjectures. 
A. Hoshino, M. Noumi and J. Shiraishi
math.CO