Infinite Series $\sum\limits_{k=1}^{\infty}\frac{k^n}{k!}$

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How can I find the value of the sum $\sum_{k=1}^{\infty}\frac{k^n}{k!}$? for example for $n=6$, we have
$$\sum_{k=1}^{\infty}\frac{k^6}{k!}=203e.$$

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The answer is $eB_n$, where $B_n$ is the $n$th Bell number. This is known as Dobinski's formula.