Hello, krazyxazn!

Your answer iscorrect!

We're expected to evaluate itwithoutcranking out the sums,

but it still takes some knowledge and quite a bit of algebra.

The inner sum is:

. .

. . . . . .

. .

Hence, the inner sum is: .

The entire sum is: .

And we have: .

We are expected to know the formulas for these three sums. . **

. .

Therefore: .

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

** . Formulas

. .

. .

. .