A closed form for the sum \(S = \frac {2}{3+1} + \frac {2^2}{3^2+1} + \cdots + \frac {2^{n+1}}{3^{2^n}+1} \) is \(1 - \frac{a^{n+b}}{3^{2^{n+c}}-1}\), where a, b, and c are integers. Find a+b+c.
a + b + c = 3 + 3 + 2 = 8.
+72 
