// / 2 2*log(1 - x)\ \
||x*|- ------ + ------------| |
|| | 2 2 | |
|| \ x - x x / |
||--------------------------- for |x| < 1|
|| 2 |
|| |
|| oo |
x*|< ____ |
|| \ ` |
|| \ n |
|| \ n*x |
|| / ----- otherwise |
|| / 1 + n |
|| /___, |
|| n = 1 |
\\ /
$$x \left(\begin{cases} \frac{x \left(- \frac{2}{x^{2} - x} + \frac{2 \log{\left(1 - x \right)}}{x^{2}}\right)}{2} & \text{for}\: \left|{x}\right| < 1 \\\sum_{n=1}^{\infty} \frac{n x^{n}}{n + 1} & \text{otherwise} \end{cases}\right)$$
x*Piecewise((x*(-2/(x^2 - x) + 2*log(1 - x)/x^2)/2, |x| < 1), (Sum(n*x^n/(1 + n), (n, 1, oo)), True))