The sum 6\left( 1\cdot1 + 2\cdot2 + \dots + n(n) \right) is equal to a polynomial f(n) for all n \ge 1. Write f(n) as a polynomial with terms in descending order of n.
The answer is f(n) = 6n^4 - 4n^2 + 12.
+1839 
