Another, well, interesting but not necessarily "challenging" problem from the series of problems that I started posting a few days ago. I hope you'll like it!
Suppose the integer is given. Evaluate
What is this, N Sums from 1 to infinity of ?
What is the context of this problem? What are you trying to do with it; Since j and n are in N, this is a subseries of , so I believe this will diverge no matter what. (could be wrong here)
Almost looks like the end of an induction proof of sorts. Let me know if I can help you work on this, looks fun.