4
This series is given in Griffiths Introduction to Electrodynamics chapter 3 in an example explaining seperation of variables.
$$V(x,y) = \frac{4V_0}{\pi} \sum_{n=1,3,5\ldots} \frac{1}{n}e^{-n\pi x/a}\sin(n\pi y/a)$$
$$V(x,y) = \frac{2V_0}{\pi} \tan^{-1}\left(\frac{\sin(\pi y/a)}{\sinh(\pi x...
