This was a step glossed over in a proof in the convergence of

that I can't seem to understand where certain terms are appearing from.

The identity is

I was able to get something similar by dividing

s on the left hand side acros the 0th term

to the

st term but that still leaves the

th and

st term untouched and with a final term not in the form of the right hand side. It also leaves

in the left hand product.

Just to illustrate what I mean I will take the case of

This is wrong: if then , and you reached up to 5...!

Tonio
Something tells me I'm making a wrong assumption somewhere or it's something dumb and obvious but I can't seem to get how this will end up in the form on the lhs.

Any help would be appreciated. Thank you for your time.