Definition:Gamma Function/Weierstrass Form

Definition
The  form of the Gamma function is:
 * $\displaystyle \frac 1 {\Gamma \left({z}\right)} = z e^{\gamma z} \prod_{n \mathop = 1}^\infty \left({\left({1 + \frac z n}\right) e^{-z / n} }\right)$

where $\gamma$ is the Euler-Mascheroni constant.

The Weierstrass form is valid for all $\C$.

Also see

 * Equivalence of Definitions of Gamma Function