1/3 - 2/9 + 3/27 - 4/81 + 5/243
$$\frac{1}{3} - \frac{2}{9} + \frac{3}{27} - \frac{4}{81} + \frac{5}{243} = \sum \limits_{n=1}^{5}(-n)(-3)^{(-n)}$$
$$\displaystyle\sum_{n=1}^{5}\;\; \frac{(-1)^{n+1}\;n}{3^n}$$
Yes, there is more than one way to skin a cat. Thanks Heureka
