This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A173636 #19 Oct 12 2018 12:14:14
%S A173636 0,0,0,1,0,1,1,1,1,2,1,1,1,1,1,4,2,1,2,1,1,4,1,1,4,2,1,3,1,1,4,1,3,4,
%T A173636 1,4,2,1,1,4,4,1,4,1,1,7,1,1,7,2,2,4,1,1,3,4,4,4,1,1,4,1,1,7,4,4,4,1,
%U A173636 1,4,4,1,7,1,1,7,1,4,4
%N A173636 Number of positive solutions of equation x(x+n)=y*y.
%C A173636 The solution x=y=0 is not counted.
%C A173636 Same as A115878 except for a(0). - _Georg Fischer_, Oct 12 2018
%F A173636 a(n) = A176835(n)-1. - _R. J. Mathar_, Nov 23 2010
%e A173636 a(9)=2 since x(x+9)=y*y has 2 solutions: x=3, y=6 and x=16, y=20.
%t A173636 Join[{0}, Table[Length[{ToRules[Reduce[x (x + n) == y^2 && x > 0 && y > 0, {x, y}, Integers]]}], {n, 100}]]
%Y A173636 Cf. A067721, A115878.
%K A173636 nonn
%O A173636 0,10
%A A173636 _Carmine Suriano_, Nov 23 2010