18.21 Hahn Class: Interrelations18.23 Hahn Class: Generating Functions

§18.22 Hahn Class: Recurrence Relations and Differences

Contents

§18.22(i) Recurrence Relations in n

Krawtchouk, Meixner, and Charlier

These polynomials satisfy (18.22.2) with p_{n}(x), A_{n}, and C_{n} as in Table 18.22.1.

Table 18.22.1: Recurrence relations (18.22.2) for Krawtchouk, Meixner, and Charlier polynomials.
p_{n}(x) A_{n} C_{n}
\mathop{K_{{n}}\/}\nolimits\!\left(x;p,N\right) p(N-n) n(1-p)
\mathop{M_{{n}}\/}\nolimits\!\left(x;\beta,c\right) \dfrac{c(n+\beta)}{1-c} \dfrac{n}{1-c}
\mathop{C_{{n}}\/}\nolimits\!\left(x,a\right) a n

Continuous Hahn

With

18.22.4 q_{n}(x)=\ifrac{\mathop{p_{{n}}\/}\nolimits\!\left(x;a,b,\conj{a},\conj{b}\right)}{\mathop{p_{{n}}\/}\nolimits\!\left(ia;a,b,\conj{a},\conj{b}\right)},
18.22.5 (a+ix)q_{{n}}(x)=\tilde{A}_{n}q_{{n+1}}(x)-\bigl(\tilde{A}_{n}+\tilde{C}_{n}\bigr)q_{n}(x)+\tilde{C}_{n}q_{{n-1}}(x),

where

18.22.6
\tilde{A}_{n}=-\frac{(n+2\realpart{(a+b)}-1)(n+a+\conj{a})(n+a+\conj{b})}{(2n+2\realpart{(a+b)}-1)(2n+2\realpart{(a+b)})},
\tilde{C}_{n}=\frac{n(n+b+\conj{a}-1)(n+b+\conj{b}-1)}{(2n+2\realpart{(a+b)}-2)(2n+2\realpart{(a+b)}-1)}.

§18.22(ii) Difference Equations in x

Hahn

With

18.22.9 p_{n}(x)=\mathop{Q_{{n}}\/}\nolimits\!\left(x;\alpha,\beta,N\right),
18.22.10 A(x)p_{n}(x+1)-\left(A(x)+C(x)\right)p_{n}(x)+C(x)p_{n}(x-1)-n(n+\alpha+\beta+1)p_{n}(x)=0,

where

18.22.11
A(x)=(x+\alpha+1)(x-N),
C(x)=x(x-\beta-N-1).

Krawtchouk, Meixner, and Charlier

Table 18.22.2: Difference equations (18.22.12) for Krawtchouk, Meixner, and Charlier polynomials.
p_{n}(x) A(x) C(x) \lambda _{n}
\mathop{K_{{n}}\/}\nolimits\!\left(x;p,N\right) p(x-N) (p-1)x -n
\mathop{M_{{n}}\/}\nolimits\!\left(x;\beta,c\right) c(x+\beta) x n(1-c)
\mathop{C_{{n}}\/}\nolimits\!\left(x,a\right) a x n

Continuous Hahn

Meixner–Pollaczek

§18.22(iii) x-Differences