Let's consider S[math]_{n}[/math]= n[math]^{2}[/math] + 20n +12. So can you find the sum of all possible n for which S[math]_{n}[/math] is a perfect square?
Let [math]S_{n} = n^{2} + 20n + 12[/math], where [math]n[/math] is a positive integer. What is the sum of all possible values of n for which [math]S_{n}[/math] is a perfect square?