Given positive integer n, consider the set of numbers {n²+1, n²+2, ... (n+1)²}. If we pick two numbers x and y out of that set, how many different values can the product xy take?
(In reply to
re(4): what am I missing? - to Josh by Josh70679)
On second thought, the answer could be either n(2n+1) or (n+1)(2n+1), depending on whether x and y must be distinct.
If they must be distinct, the answer is n(2n+1),
but if we allow x = y, the answer is (n+1)(2n+1).
wait a second...
