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 A227201 #31 Sep 20 2013 15:26:18
%S A227201 1072493856,1075948326,1235976840,1239084756,1253684790,1253894670,
%T A227201 1263984750,1265738940,1270953864,1279635840,1287349560,1287463950,
%U A227201 1295738640,1297836540,1298647350,1328405976,1329754860,1346589720,1357962840,1376925480,1382974560
%N A227201 Areas of Pythagorean triangles with areas that use all ten decimal digits exactly once.
%C A227201 There are 515 members to the set.
%H A227201 T. D. Noe, <a href="/A227201/b227201.txt">Table of n, a(n) for n = 1..515</a>
%t A227201 mx = 10^10; mn = mx/10; nn = Ceiling[mx^(1/3)]; If[OddQ[nn], nn + 1]; t = Union[Flatten[Table[If[GCD[u, v] == 1 && Mod[u, 2] + Mod[v, 2] == 1, u v (u^2 - v^2), 0], {u, nn}, {v, u - 1}]]]; t2 = Select[Rest[t], # < mx &]; t3 = {}; Do[num0 = Ceiling[Sqrt[mn/n]]; num1 = Floor[Sqrt[mx/n]]; Do[num = i^2*n; If[Length[Union[IntegerDigits[num]]] == 10, AppendTo[t3, num]], {i, num0, num1}], {n, t2}]; t3 = Union[t3] (* _T. D. Noe_, Sep 20 2013 *)
%Y A227201 Cf. A024365.
%K A227201 nonn,base,fini,full
%O A227201 1,1
%A A227201 _Charles Kluepfel_, Sep 18 2013