
Help with series
Hello everyone, I'm kind of new here so wasn't sure where to post a series problem.
How would one go about summing
$\displaystyle \displaystyle \sum_{i=0}^{\infty} \frac{1}{(3i)!}$
I've tried to find similarities between it and the taylor series of hyperbolic cosine, but it isn't really working. I've tried repeated integration to derive a result with the factorial in the denominator but again, I get a nonconvergent integral. Any help would be appreciated, thank you.

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Re: Help with series
Hi,
Your problem has a straight forward solution, but the details require some computation. The attachment shows how to solve the problem, but I left the algebraic details to you:
Attachment 28846