# §13.25 Products

 13.25.1 $\mathop{M_{\kappa,\mu}\/}\nolimits\!\left(z\right)\mathop{M_{\kappa,-\mu-1}\/}% \nolimits\!\left(z\right)+\frac{(\frac{1}{2}+\mu+\kappa)(\frac{1}{2}+\mu-% \kappa)}{4\mu(1+\mu)(1+2\mu)^{2}}\mathop{M_{\kappa,\mu+1}\/}\nolimits\!\left(z% \right)\mathop{M_{\kappa,-\mu}\/}\nolimits\!\left(z\right)=1.$

For integral representations, integrals, and series containing products of $\mathop{M_{\kappa,\mu}\/}\nolimits\!\left(z\right)$ and $\mathop{W_{\kappa,\mu}\/}\nolimits\!\left(z\right)$ see Erdélyi et al. (1953a, §6.15.3).