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 A041123 #23 Jul 09 2025 00:18:11
%S A041123 1,2,3,8,11,30,491,1012,1503,4018,5521,15060,246481,508022,754503,
%T A041123 2017028,2771531,7560090,123732971,255026032,378759003,1012544038,
%U A041123 1391303041,3795150120,62113704961,128022560042
%N A041123 Denominators of continued fraction convergents to sqrt(70).
%H A041123 Vincenzo Librandi, <a href="/A041123/b041123.txt">Table of n, a(n) for n = 0..200</a>
%H A041123 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,502,0,0,0,0,0,-1).
%F A041123 a(n) = 502*a(n-6)-a(n-12). G.f.: -(x^2-2*x-1)*(x^8+4*x^6+15*x^4+4*x^2+1)/ (x^12-502*x^6+1). [_Colin Barker_, Jul 18 2012]
%t A041123 Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[70],n]]],{n,1,50}] (* _Vladimir Joseph Stephan Orlovsky_, Jun 26 2011 *)
%t A041123 Denominator[Convergents[Sqrt[70], 30]] (* _Vincenzo Librandi_, Oct 24 2013 *)
%Y A041123 Cf. A010522, A041122.
%K A041123 nonn,cofr,frac,easy
%O A041123 0,2
%A A041123 _N. J. A. Sloane_