Weierstrass zeta
From specialfunctionswiki
Let $\Lambda \subset \mathbb{C}$ be a lattice. The Weierstrass zeta function is defined by $$\zeta(z;\Lambda)=\dfrac{1}{z} + \displaystyle\sum_{w \in \Lambda \setminus \{0\}}\left( \dfrac{1}{z-w} + \dfrac{1}{w} + \dfrac{z}{w^2} \right).$$
