A double-square number is an integer X which can be expressed as the
sum of two perfect squares. For example, 10 is a double-square because 10 =
32 + 12. Your task in this problem is, given X,
determine the number of ways in which it can be written as the sum of two
squares. For example, 10 can only be written as 32 + 12
(we don't count 12 + 32 as being different). On the
other hand, 25 can be written as 52 + 02 or as
42 + 32.