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 A041131 #21 Jul 09 2025 00:19:00
%S A041131 1,1,2,3,5,83,88,171,259,430,7139,7569,14708,22277,36985,614037,
%T A041131 651022,1265059,1916081,3181140,52814321,55995461,108809782,164805243,
%U A041131 273615025,4542645643,4816260668,9358906311,14175166979,23534073290,390720339619,414254412909
%N A041131 Denominators of continued fraction convergents to sqrt(74).
%H A041131 Vincenzo Librandi, <a href="/A041131/b041131.txt">Table of n, a(n) for n = 0..200</a>
%H A041131 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,86,0,0,0,0,1).
%F A041131 G.f.: -(x^4-3*x^3+4*x^2-2*x+1)*(x^4+2*x^3+4*x^2+3*x+1) / (x^10+86*x^5-1). - _Colin Barker_, Nov 13 2013
%F A041131 a(n) = 86*a(n-5) + a(n-10). - _Vincenzo Librandi_, Dec 11 2013
%t A041131 Denominator/@Convergents[Sqrt[74], 50] (* _Vladimir Joseph Stephan Orlovsky_, Jul 05 2011 *)
%t A041131 CoefficientList[Series[-(x^4 - 3 x^3 + 4 x^2 - 2 x + 1) (x^4 + 2 x^3 + 4 x^2 + 3 x + 1)/(x^10 + 86 x^5 - 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Dec 11 2013 *)
%t A041131 LinearRecurrence[{0,0,0,0,86,0,0,0,0,1},{1,1,2,3,5,83,88,171,259,430},50] (* _Harvey P. Dale_, Nov 09 2017 *)
%o A041131 (Magma) I:=[1, 1, 2, 3, 5, 83, 88, 171, 259, 430]; [n le 10 select I[n] else 86*Self(n-5)+Self(n-10): n in [1..40]]; // _Vincenzo Librandi_, Dec 11 2013
%Y A041131 Cf. A041130, A010152, A020831, A010526.
%K A041131 nonn,cofr,frac,easy
%O A041131 0,3
%A A041131 _N. J. A. Sloane_