# May I Borrow Your Telescope?

Calculus Level 4

$\large \sum_{i=1}^{\infty} \frac{(-1)^i (i^2 + i + 1)}{i!} =\, ?$

 Notation: $$!$$ is the factorial notation. For example, $$8! = 1\times2\times3\times\cdots\times8$$.

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