or something like that. I'm not thinking very carefully about the indices and have to run, but this is the idea. Correct it where appropriate.
Yes, sorry I meant -1 of course.
What I think you're trying to do is this:
Let so that
If that's what you mean, then your next part is wrong, since the identity in my first post doesn't apply.
Or did I misunderstand?
Think about the particular case of the product that arises when . There is then only one term in the product, and it is equal to . For most values of n, there is no explicit formula for in terms of more elementary functions of n. So even in that special case, there is no satisfactory solution to the problem.