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 A082657 #10 Dec 08 2019 12:24:35
%S A082657 1,2,3,4,5,6,11,12,14,16,17,21,24,25,29,30,32,35,36,39,42,44,49,50,51,
%T A082657 53,54,56,57,65,66,71,72,74,75,77,78,80,81,84,95,96,101,104,105,107,
%U A082657 110,116,117,119,120,122,126,128,129,131,137,141,149,150,152,153,156,161
%N A082657 Integers expressible as the sum of a square and a triangular number in just one way.
%C A082657 It is assumed here that 0 is a square but not a triangular number. - _Amiram Eldar_, Dec 08 2019
%H A082657 Amiram Eldar, <a href="/A082657/b082657.txt">Table of n, a(n) for n = 1..10000</a>
%t A082657 aQ[n_] := Length @ Solve[x^2 + y (y + 1)/2 == n && x >= 0 && y > 0, {x, y}, Integers] == 1; Select[Range[161], aQ] (* _Amiram Eldar_, Dec 08 2019 *)
%Y A082657 Cf. A000217, A000290, A082658, A082659, A082660.
%K A082657 nonn
%O A082657 1,2
%A A082657 _Jason Earls_, May 17 2003