I came accross this series:
$\sum_{i=p}^{n}{e^{-i(d+i)}}$ with $d \in \mathbb{R}^+$
This looks like a geometric series but it is not. How do I compute its limit when $n \rightarrow +\infty$ ? Which object extends the geometrical series to polynomial exponents?
EDIT: this turns out to be a particular case of this problem which seems to have no general solution yet.
