Answer
$$\frac{e}{e^2-1}$$
Work Step by Step
Given
$$ \sum_{n=2}^{n=\infty} e^{3-2 n}=\sum_{n=2}^{n=\infty} e^{3}\left(\frac{1}{e^{2}}\right)^{n}$$
Since the series is a geometric series with $|r|=\left|\frac{1}{e^2}\right|<1$ , then the series converges and has the sum
\begin{align*}
S&= \frac{a_1}{1-r}\\
&=\frac{\frac{1}{e}}{1-\frac{1}{e^2}}\\
&=\frac{e}{e^2-1}
\end{align*}