I have the sums:
$$ \sum_{i=0}^{n-1} \sum_{j=0}^{i} \sum_{k=1}^{\frac{n}{2^j}} 1 $$
This is the sum representation of a triple nested for loop. Normally, I can do these kinds of problems, however due to the $\frac{n}{2^j}$, I have no idea where to even begin on this problem. How can I proceed from here? I would appreciate if you explained each step that you took and maybe the thought process behind it, especially with regards to what is done with the third summation.