A049252 Smallest nonnegative value taken on by 13x^2 - ny^2 for an infinite number of integer pairs (x, y).

1, 2, 1, 1, 5, 7, 5, 5, 1, 3, 2, 1, 0, 13, 13, 4, 13, 13, 2, 5, 7, 10, 1, 13, 12, 13, 1, 5, 1, 13, 6, 5, 7, 13, 10, 1, 5, 10, 13, 12, 7, 3, 1, 8, 7, 2, 5, 4, 3, 2, 1, 0, 13, 13, 13, 13, 13, 5, 2, 13, 1, 13, 13, 13, 13, 13, 2, 13, 13, 7, 13, 13, 5, 13, 13, 8, 13, 13, 1, 5, 1, 3, 2, 13, 8, 13