// / x\ \
||-3*log|1 - -| |
|| \ 3/ |
||------------- for And(x >= -3, x < 3)|
|| x |
|| |
|| oo |
x*|<____ |
||\ ` |
|| \ -n n |
|| \ 3 *x |
|| / ------ otherwise |
|| / 1 + n |
||/___, |
\\n = 0 /
-------------------------------------------
3
$$\frac{x \left(\begin{cases} - \frac{3 \log{\left(1 - \frac{x}{3} \right)}}{x} & \text{for}\: x \geq -3 \wedge x < 3 \\\sum_{n=0}^{\infty} \frac{3^{- n} x^{n}}{n + 1} & \text{otherwise} \end{cases}\right)}{3}$$
x*Piecewise((-3*log(1 - x/3)/x, (x >= -3)∧(x < 3)), (Sum(3^(-n)*x^n/(1 + n), (n, 0, oo)), True))/3