$\"\"$

The series is $\"\"$ .

The lower bound is $\"\"$ .

Rewrite the series as $\"\"$ .

The sigma notantion is $\"\"$ , where $\"\"$ is upper bound and $\"\"$ is lower bound.

Here, $\"\"$ and $\"\"$ .

$\"\"$ .

The sigma notation is $\"\"$ .

$\"\"$

$\"\"$ .