Mittag-Leffler Expansion for Square of Cosecant Function

Theorem

 * $\ds \pi^2 \map {\csc^2} {\pi z} = \frac 1 {z^2} + 2 \sum_{n \mathop = 1}^\infty \frac {z^2 + n^2} {\paren {z^2 - n^2}^2}$

where:
 * $z$ is a complex number that is not a integer
 * $\csc$ denotes the cosecant function.