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 A207060 #19 Feb 16 2025 08:33:16
%S A207060 0,259,496,1203,2596,3939,8020,16119,23940,47719,94920,140503,279096,
%T A207060 554203,819880,1627659,3231100,4779579,9487660,18833199,27858396,
%U A207060 55299103,109768896,162371599,322307760,639780979,946372000,1878548259,3728917780,5515861203
%N A207060 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+401)^2 = y^2.
%H A207060 Vincenzo Librandi, <a href="/A207060/b207060.txt">Table of n, a(n) for n = 1..1000</a>
%H A207060 Wikipedia, <a href="http://en.wikipedia.org/wiki/Diophantine_equation">Diophantine equation</a>
%H A207060 MathWorld, <a href="https://mathworld.wolfram.com/DiophantineEquation.html">Diophantine equation</a>
%H A207060 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,6,-6,0,-1,1).
%F A207060 G.f.: x^2*(161*x^5+79*x^4+161*x^3-707*x^2-237*x-259)/((x-1)*(x^6-6*x^3+1)). - _Colin Barker_, Aug 05 2012
%t A207060 LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 259, 496, 1203, 2596, 3939, 8020}, 50]
%Y A207060 Cf. A204765, A205644, A205672, A207058, A207059.
%K A207060 nonn,easy
%O A207060 1,2
%A A207060 _Vladimir Joseph Stephan Orlovsky_, Feb 14 2012