# Sum of odd squares

Algebra Level 3

The sum of squares formula is given by

$1^2 + 2^2 + 3^2 + \ldots + n^2 = \frac { n(n+1) (2n+1) } {6}.$

The sum of odd squares can be expressed as

$1^2 + 3^2 + 5 ^2 + \ldots + (2n-1)^2 = An^3 + Bn^2 + Cn + D.$

The value of $$A$$ can be expressed as $$\frac{a}{b}$$, where $$a$$ and $$b$$ are positive coprime integers. What is the value of $$a+b$$?

×