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 A230644 #20 Mar 02 2014 08:15:07
%S A230644 2,20,65,41,1475,15939,60422,68880,1063438,12631900,55535695,86719879,
%T A230644 743336365,9948240141,50564635018,96971881440,496655601122,
%U A230644 7778740572980,45669244934945,101577438080201,308633722311395,6032082927439779,40960925870541542
%N A230644 Values of x such that x^2 + y^2 = 29^n with x and y coprime and 0 < x < y.
%C A230644 The corresponding y-values are in A230645.
%H A230644 Vincenzo Librandi, <a href="/A230644/b230644.txt">Table of n, a(n) for n = 1..200</a>
%e A230644 a(3)=65 because 65^2+142^2=24389=29^3.
%t A230644 Table[Select[PowersRepresentations[29^n, 2, 2], CoprimeQ@@#&][[1, 1]], {n, 1, 40}] (* _Vincenzo Librandi_, Mar 02 2014 *)
%Y A230644 Cf. A009973, A188948, A230622, A230645.
%K A230644 nonn
%O A230644 1,1
%A A230644 _Colin Barker_, Oct 26 2013
%E A230644 Incorrect formula deleted by _Colin Barker_, Jan 08 2014