What's New
About the Project
NIST
20 Theta FunctionsProperties

§20.8 Watson’s Expansions

20.8.1 θ2(0,q)θ3(z,q)θ4(z,q)θ2(z,q)=2n=-(-1)nqn2ei2nzq-ne-iz+qneiz.

See Watson (1935a). This reference and Bellman (1961, pp. 46–47) include other expansions of this type.