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 A289219 #11 Aug 06 2017 14:27:40
%S A289219 192,204,210,216,240,252,264,270,324,330,336,378,384,408,420,456,462,
%T A289219 480,504,522,540,546,624,690,714,780,792,840,876,966,990,1176,1248,
%U A289219 1320,1380,1806,2394,2460,3120,4446,8436
%N A289219 Areas of integer-sided triangles whose area equals 3 times their perimeter.
%C A289219 There are no further terms.
%C A289219 For a(3)=210, there are 2 solutions (20,21,29),(17,25,28);
%C A289219 For a(11)=336, there are 2 solutions (14,48,50),(24,35,53);
%C A289219 For a(16)=456, a(22)=546, there are 2 solutions respectively too.
%e A289219 The areas 192,204,210,216,240, ... pertain respectively to triangles with sides (20,20,24), (17,25,26), (20,21,29), (18,24,30), (16,30,34), ..., equal 3 times their perimeter 64,68,70,72,80, ...
%t A289219 f[a_, b_, c_] := Block[{P = Total[{a, b, c}]/2}, Sqrt[P (P - a) (P - b) (P - c)]]; Sort@ Map[f @@ # &, Select[Union@ Map[Sort, Tuples[Range@ 150, {3}]], f @@ # == 3 Total@# &] ] (* _Michael De Vlieger_, Jul 03 2017 *)
%Y A289219 Cf. A098030, A289218.
%Y A289219 A row of the triangle in A290451.
%K A289219 nonn,fini,full
%O A289219 1,1
%A A289219 _Zhining Yang_, Jun 28 2017