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 A230841 #15 Mar 03 2014 02:46:18
%S A230841 5,11,234,1320,9475,117469,266286,9184560,3302155,520632300,
%T A230841 1387108806,23922442439,154165737965,933420304380,13338456688674,
%U A230841 22995028210081,1026964091673115,713853567388260,54078566783400895,171226928056302601,2435077776719657394
%N A230841 Values of x such that x^2 + y^2 = 61^n with x and y coprime and 0 < x < y.
%C A230841 The corresponding y-values are in A230842.
%H A230841 Vincenzo Librandi, <a href="/A230841/b230841.txt">Table of n, a(n) for n = 1..200</a>
%e A230841 a(3)=234 because 234^2+415^2=226981=61^3.
%t A230841 Table[Select[PowersRepresentations[61^n, 2, 2], CoprimeQ[#[[1]], #[[2]]] &][[1, 1]], {n, 22}] (* _T. D. Noe_, Nov 04 2013 *)
%t A230841 Table[Select[PowersRepresentations[61^n, 2, 2], CoprimeQ@@#&][[1, 1]], {n, 1, 40}] (* _Vincenzo Librandi_, Mar 02 2014 *)
%Y A230841 Cf. A230842, A188948, A230622, A230644, A230710, A230712, A230743, A230759.
%K A230841 nonn
%O A230841 1,1
%A A230841 _Colin Barker_, Oct 31 2013
%E A230841 a(10) and a(20) corrected by _Zak Seidov_, Nov 02 2013