Let "a" and "b" be two positive integers such that ab + 1 divides a^2 + b^2. Show that: a^2 + b^2 / ab + 1 is the square of an integer.
a =2 and b=8, because:
2^2+8^2 =68 and 2 x 8 + 1 =17
68/17 =4, which the square of 2.
