Sum of Sequence of Squares/Proof by Binomial Coefficients

Proof
From Binomial Coefficient with One:
 * $\dbinom n 1 = n$

From Binomial Coefficient with Two:
 * $\dbinom n 2 = \dfrac {n \paren {n - 1} } 2$

Thus:

Hence:

Also see

 * Sum of Sequence of Fourth Powers/Proof using Binomial Coefficients