@article {MATHEDUC.06164064,
author = {Wright, Cory and Osler, Thomas J.},
title = {Four derivations of an interesting bilateral series generalizing the series for zeta of 2.},
year = {2013},
journal = {International Journal of Mathematical Education in Science and Technology},
volume = {44},
number = {3},
issn = {0020-739X},
pages = {456-461},
publisher = {Taylor \& Francis, Abingdon, Oxfordshire},
doi = {10.1080/0020739X.2012.714495},
abstract = {Summary: We present four derivations of the closed form of the partial fractions expansion $$\pi \left(\dfrac{\cot \pi a}{b-a}-\dfrac{\cot \pi b}{a-b}\right) = \sum_{n=-\infty}^{\infty}\dfrac{1}{(n+a)(n+b)}.$$ This interesting series is a generalization of the series $\frac{\pi ^2}{6}= \sum_{n=1}^{\infty} \frac{1}{n^2} = \zeta(2)$ made famous by Euler.},
msc2010 = {F65xx (I45xx I55xx)},
identifier = {2013c.00433},
}