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 A041119 #22 Jul 09 2025 00:17:46
%S A041119 1,4,65,264,4289,17420,283009,1149456,18674305,75846676,1232221121,
%T A041119 5004731160,81307919681,330236409884,5365090477825,21790598321184,
%U A041119 354014663616769,1437849252788260,23359602708228929,94876260085703976,1541379764079492545
%N A041119 Denominators of continued fraction convergents to sqrt(68).
%H A041119 Vincenzo Librandi, <a href="/A041119/b041119.txt">Table of n, a(n) for n = 0..200</a>
%H A041119 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,66,0,-1).
%F A041119 G.f.: -(x^2-4*x-1) / ((x^2-8*x-1)*(x^2+8*x-1)). - _Colin Barker_, Nov 13 2013
%F A041119 a(n) = 66*a(n-2) - a(n-4). - _Vincenzo Librandi_, Dec 11 2013
%t A041119 Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[68],n]]],{n,1,50}] (* _Vladimir Joseph Stephan Orlovsky_, Jun 26 2011 *)
%t A041119 Denominator[Convergents[Sqrt[68], 30]] (* _Vincenzo Librandi_, Dec 11 2013 *)
%o A041119 (Magma) I:=[1, 4, 65, 264]; [n le 4 select I[n] else 66*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Dec 11 2013
%Y A041119 Cf. A041118, A040059, A020825, A010520.
%K A041119 nonn,cofr,easy,frac
%O A041119 0,2
%A A041119 _N. J. A. Sloane_
%E A041119 More terms from _Colin Barker_, Nov 13 2013