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 A207058 #14 Jun 18 2017 02:25:47
%S A207058 0,145,364,789,1564,2805,5260,9765,16992,31297,57552,99673,183048,
%T A207058 336073,581572,1067517,1959412,3390285,6222580,11420925,19760664,
%U A207058 36268489,66566664,115174225,211388880,387979585,671285212,1232065317,2261311372,3912537573
%N A207058 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+263)^2 = y^2.
%H A207058 Vincenzo Librandi, <a href="/A207058/b207058.txt">Table of n, a(n) for n = 1..1000</a>
%H A207058 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,6,-6,0,-1,1).
%F A207058 G.f.: x^2*(95*x^5+73*x^4+95*x^3-425*x^2-219*x-145)/((x-1)*(x^6-6*x^3+1)). [_Colin Barker_, Aug 05 2012]
%t A207058 LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 145, 364, 789, 1564, 2805, 5260}, 40]
%Y A207058 Cf. A204765, A205644, A205672
%K A207058 nonn,easy
%O A207058 1,2
%A A207058 _Vladimir Joseph Stephan Orlovsky_, Feb 14 2012