A176836 Number of pairs (a, b) of positive integers with a <= b such that both a^2 - nb and b^2 - na are squares.

1, 1, 4, 2, 6, 4, 8, 7, 12, 6, 10, 15, 14, 8, 26, 21, 16, 12, 16, 30, 32

Offset: 1

Author

Jens Voß, Apr 27 2010

Keywords

• nonn

Examples

			a(4) = 2 because the pairs (4, 4) and (5, 6) have the specified property: 4^4 - 4*4 = 0^2; 5^2 - 4*6 = 1^2, 6^2 - 4*5 = 4^2.
		

Crossrefs

a(n) = A176835(n) + A176837(n)