%I #2 Mar 31 2012 14:45:33
%S 0,0,2,1,4,2,6,5,9,4,8,13,12,6,21,18,14,9,14,28,27
%N Number of pairs (a, b) of positive integers with a < b such that both a^2 - nb and b^2 - na are squares
%e A176837(3) = 2 because the pairs (5, 8) and (7, 11) have the specified property: 5^2 - 3*8 = 1^2, 8^2 - 3*5 = 7^2; 7^2 - 3*11 = 4^2, 11^2 - 3*7 = 10^2.
%Y A176837(n) = A176836(n) - A176835(n)
%K nonn
%O 1,3
%A _Jens Voß_, Apr 27 2010