# Thread: convergent or divergent partial sum

1. ## convergent or divergent partial sum

how do I find out if this partial sum is divergent or convergent

$\sum\frac{1}{2^{k+1}-1}$

what is confusing me is the $2^{k+1}$ and how can I use a basic or limit comparison test or integral test to find this out?

2. Originally Posted by akhayoon
how do I find out if this partial sum is divergent or convergent $\sum\frac{1}{2^{k+1}-1}$
limit comparison test
We know that $\sum {\frac{1}{{2^{k + 1} }}}$.
Now use the test.