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 A207639 #7 Aug 11 2015 01:14:58
%S A207639 225,361,441,529,625,729,841,900,961,1089,1225,1369,1444,1521,1681,
%T A207639 1764,1849,2025,2116,2209,2401,2500,2601,2809,2916,3025,3249,3364,
%U A207639 3481,3600,3721,3844,3969,4225,4356,4489,4761,4900,5041,5329,5476,5625,5776,5929
%N A207639 Squares that can be written as a sum of 3 distinct nonzero squares in more than one way.
%t A207639 t = Sort[Select[Flatten[Table[x^2 + y^2 + z^2, {x, 400}, {y, x + 1, 400}, {z, y + 1, 400}]], # < 160006 && IntegerQ[Sqrt[#]] &]];
%t A207639 f1[l_] := Module[{t = {}}, Do[If[l[[n]] != l[[n + 1]] && l[[n]] != l[[n - 1]], AppendTo[t, l[[n]]]], {n, Length[l] - 1}]; t];
%t A207639 s1 = Join[{First[t]}, f1[t]];
%t A207639 Complement[t, s1]
%K A207639 nonn
%O A207639 1,1
%A A207639 _Vladimir Joseph Stephan Orlovsky_, Feb 19 2012