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 A082659 #15 Dec 08 2019 12:25:18
%S A082659 10,19,46,64,82,109,121,127,154,169,217,253,257,262,271,316,352,361,
%T A082659 379,397,400,451,460,478,487,496,505,514,529,586,620,640,649,667,694,
%U A082659 721,757,767,856,865,910,937,961,964,991,1045,1054,1072,1099,1104,1135,1153
%N A082659 Integers expressible as the sum of a square and a triangular number in exactly three distinct ways.
%C A082659 It is assumed here that 0 is a square but not a triangular number. - _Amiram Eldar_, Dec 08 2019
%H A082659 Amiram Eldar, <a href="/A082659/b082659.txt">Table of n, a(n) for n = 1..10000</a>
%e A082659 a(5) = 82 because 82 = 1 + 81; 82 = 66 + 16; 82 = 78 + 4.
%t A082659 aQ[n_] := Length @ Solve[x^2 + y (y + 1)/2 == n && x >= 0 && y > 0, {x, y}, Integers] == 3; Select[Range[1200], aQ] (* _Amiram Eldar_, Dec 08 2019 *)
%Y A082659 Cf. A000217, A000290, A082657, A082658, A082660.
%K A082659 nonn
%O A082659 1,1
%A A082659 _Jason Earls_, May 17 2003
%E A082659 Name clarified by _Amiram Eldar_, Dec 08 2019