For comments on the use of the forward-difference operator , the
backward-difference operator , and the central-difference operator
, see §18.2(ii).
In (18.20.1) and are as in Table 18.19.1.
For the Hahn polynomials and
For the Krawtchouk, Meixner, and Charlier polynomials, and
are as in Table 18.20.1.
For the definition of hypergeometric and generalized hypergeometric functions see §16.2.
(For symmetry properties of with
respect to , , , see
Andrews et al. (1999, Corollary 3.3.4).)