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 A041760 #31 Jul 09 2025 01:22:58 %S A041760 20,801,32060,1283201,51360100,2055687201,82278848140,3293209612801, %T A041760 131810663360180,5275719744020001,211160600424160220, %U A041760 8451699736710428801,338279150068841312260,13539617702490362919201,541922987249683358080300 %N A041760 Numerators of continued fraction convergents to sqrt(401). %H A041760 Vincenzo Librandi, <a href="/A041760/b041760.txt">Table of n, a(n) for n = 0..200</a> %H A041760 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A041760 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (40,1). %F A041760 a(n) = 40*a(n-1)+a(n-2) for n>1, a(0)=20, a(1)=801. G.f.: (20+x)/(1-40*x-x^2). [_Philippe Deléham_, Nov 23 2008] %t A041760 Numerator[Convergents[Sqrt[401], 30]] (* _Vincenzo Librandi_, Nov 07 2013 *) %Y A041760 Cf. A041761, A040380. %K A041760 nonn,cofr,frac,easy,less %O A041760 0,1 %A A041760 _N. J. A. Sloane_