Digital Library of Mathematical Functions
About the Project
NIST
18 Orthogonal PolynomialsClassical Orthogonal Polynomials

§18.9 Recurrence Relations and Derivatives

Contents

§18.9(i) Recurrence Relations

18.9.1p_{{n+1}}(x)=(A_{n}x+B_{n})p_{n}(x)-C_{n}p_{{n-1}}(x).

For p_{n}(x)=\mathop{P^{{(\alpha,\beta)}}_{{n}}\/}\nolimits\!\left(x\right),

For the other classical OP’s see Table 18.9.1; compare also §18.2(iv).

Table 18.9.1: Classical OP’s: recurrence relations (18.9.1).
p_{n}(x) A_{n} B_{n} C_{n}
\mathop{C^{{(\lambda)}}_{{n}}\/}\nolimits\!\left(x\right) \frac{2(n+\lambda)}{n+1} 0 \frac{n+2\lambda-1}{n+1}
\mathop{T_{{n}}\/}\nolimits\!\left(x\right) 2-\delta_{{n,0}} 0 1
\mathop{U_{{n}}\/}\nolimits\!\left(x\right) 2 0 1
\mathop{T^{{*}}_{{n}}\/}\nolimits\!\left(x\right) 4-2\delta_{{n,0}} -2+\delta_{{n,0}} 1
\mathop{U^{{*}}_{{n}}\/}\nolimits\!\left(x\right) 4 −2 1
\mathop{P_{{n}}\/}\nolimits\!\left(x\right) \frac{2n+1}{n+1} 0 \frac{n}{n+1}
\mathop{P^{{*}}_{{n}}\/}\nolimits\!\left(x\right) \frac{4n+2}{n+1} -\frac{2n+1}{n+1} \frac{n}{n+1}
\mathop{L^{{(\alpha)}}_{{n}}\/}\nolimits\!\left(x\right) -\frac{1}{n+1} \frac{2n+\alpha+1}{n+1} \frac{n+\alpha}{n+1}
\mathop{H_{{n}}\/}\nolimits\!\left(x\right) 2 0 2n
\mathop{\mathit{He}_{{n}}\/}\nolimits\!\left(x\right) 1 0 n

§18.9(ii) Contiguous Relations in the Parameters and the Degree

Jacobi

18.9.3\mathop{P^{{(\alpha,\beta-1)}}_{{n}}\/}\nolimits\!\left(x\right)-\mathop{P^{{(%
\alpha-1,\beta)}}_{{n}}\/}\nolimits\!\left(x\right)=\mathop{P^{{(\alpha,\beta)%
}}_{{n-1}}\/}\nolimits\!\left(x\right),
18.9.4(1-x)\mathop{P^{{(\alpha+1,\beta)}}_{{n}}\/}\nolimits\!\left(x\right)+(1+x)%
\mathop{P^{{(\alpha,\beta+1)}}_{{n}}\/}\nolimits\!\left(x\right)=2\!\mathop{P^%
{{(\alpha,\beta)}}_{{n}}\/}\nolimits\!\left(x\right).
18.9.5(2n+\alpha+\beta+1)\mathop{P^{{(\alpha,\beta)}}_{{n}}\/}\nolimits\!\left(x%
\right)=(n+\alpha+\beta+1)\mathop{P^{{(\alpha,\beta+1)}}_{{n}}\/}\nolimits\!%
\left(x\right)+(n+\alpha)\mathop{P^{{(\alpha,\beta+1)}}_{{n-1}}\/}\nolimits\!%
\left(x\right),
18.9.6(n+\tfrac{1}{2}\alpha+\tfrac{1}{2}\beta+1)(1+x)\mathop{P^{{(\alpha,\beta+1)}}_%
{{n}}\/}\nolimits\!\left(x\right)=(n+1)\mathop{P^{{(\alpha,\beta)}}_{{n+1}}\/}%
\nolimits\!\left(x\right)+(n+\beta+1)\mathop{P^{{(\alpha,\beta)}}_{{n}}\/}%
\nolimits\!\left(x\right),

and a similar pair to (18.9.5) and (18.9.6) by symmetry; compare the second row in Table 18.6.1.

Laguerre

§18.9(iii) Derivatives