Test the uniform convergence of the series
$$ \sum_{n=1}^\infty \frac{1}{z^2 - n^2 \pi^2}$$
$$ \forall z \not= \pm n\pi,\;\; where n \in\mathbb N$$
Can I find $M_n$ such that $$ \sum_{n=1}^\infty \frac{1}{z^2 - n^2 \pi^2}\lt \sum_{n=1}^{+\infty}M_n<+\infty\;\;\;\;\;\;\;?$$
Actually, if $|z2−n2π2|≥n2π2$, then your initial inequality holds.