A quadratic formula for basic hypergeometric series related to   Askey-Wilson polynomials
  We prove a general quadratic formula for basic hypergeometric series, from which simple proofs of several recent determinant and Pfaffian formulas are obtained. A special case of the quadratic formula is actually related to a Gram determinant formula for Askey-Wilson polynomials. We also show how to derive a recent double-sum formula for the moments of Askey-Wilson polynomials from Newton's interpolation formula. 
Victor J. W. Guo, Masao Ishikawa, Hiroyuki Tagawa, Jiang Zeng
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