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 A041439 #21 Jul 09 2025 00:50:06
%S A041439 1,3,91,276,8371,25389,770041,2335512,70835401,214841715,6516086851,
%T A041439 19763102268,599409154891,1817990566941,55139126163121,
%U A041439 167235369056304,5072200197852241,15383835962613027,466587279076243051,1415145673191342180,42920957474816508451
%N A041439 Denominators of continued fraction convergents to sqrt(235).
%H A041439 Vincenzo Librandi, <a href="/A041439/b041439.txt">Table of n, a(n) for n = 0..200</a>
%H A041439 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0, 92, 0, -1).
%F A041439 G.f.: -(x^2-3*x-1) / (x^4-92*x^2+1). - _Colin Barker_, Nov 17 2013
%F A041439 a(n) = 92*a(n-2) - a(n-4). - _Vincenzo Librandi_, Dec 17 2013
%t A041439 Denominator[Convergents[Sqrt[235], 30]] (* _Vincenzo Librandi_, Dec 17 2013 *)
%t A041439 LinearRecurrence[{0,92,0,-1},{1,3,91,276},30] (* _Harvey P. Dale_, May 05 2018 *)
%o A041439 (Magma) I:=[1,3,91,276]; [n le 4 select I[n] else 92*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Dec 17 2013
%Y A041439 Cf. A041438, A176524, A040219.
%K A041439 nonn,frac,easy
%O A041439 0,2
%A A041439 _N. J. A. Sloane_
%E A041439 More terms from _Colin Barker_, Nov 17 2013