// / pi*I\ \
||-polylog\2, x*e / |
||--------------------- for |x| <= 1|
|| x |
|| |
|| oo |
|| ____ |
x*|< \ ` |
|| \ n n |
|| \ (-1) *x |
|| ) ------------ otherwise |
|| / 2 |
|| / 1 + n + 2*n |
|| /___, |
\\ n = 0 /
$$x \left(\begin{cases} - \frac{\operatorname{Li}_{2}\left(x e^{i \pi}\right)}{x} & \text{for}\: \left|{x}\right| \leq 1 \\\sum_{n=0}^{\infty} \frac{\left(-1\right)^{n} x^{n}}{n^{2} + 2 n + 1} & \text{otherwise} \end{cases}\right)$$
x*Piecewise((-polylog(2, x*exp_polar(pi*i))/x, |x| <= 1), (Sum((-1)^n*x^n/(1 + n^2 + 2*n), (n, 0, oo)), True))