How to Compute The Sum of Squares for First N Integers

We need to find,
	answer
How to get that?
Let’s consider the expansion of
Therefore,
Now let’s substitute values for
	when
	when
…
	when
	when
if you sum them from top to bottom
Taking the sum of arithmetic series,
Therefore,

Special thanks to my friend Jayampathi Rathnayake (http://www.math.indiana.edu/people/profile.phtml?id=jratnaya) for his insight on the approach.

Another good resource http://www.trans4mind.com/personal_development/mathematics/series/sumNaturalSquares.htm