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 A042151 #18 Jul 09 2025 02:20:15
%S A042151 1,2,97,196,9505,19206,931393,1881992,91267009,184416010,8943235489,
%T A042151 18070886988,876345810913,1770762508814,85872946233985,
%U A042151 173516654976784,8414672385119617,17002861425216018,824552020795488481,1666106903016192980,80797683365572751521
%N A042151 Denominators of continued fraction convergents to sqrt(600).
%H A042151 Vincenzo Librandi, <a href="/A042151/b042151.txt">Table of n, a(n) for n = 0..200</a>
%H A042151 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,98,0,-1).
%F A042151 G.f.: -(x^2-2*x-1) / ((x^2-10*x+1)*(x^2+10*x+1)). - _Colin Barker_, Dec 02 2013
%F A042151 a(n) = 98*a(n-2) - a(n-4) for n>3. - _Vincenzo Librandi_, Jan 15 2014
%t A042151 Denominator[Convergents[Sqrt[600], 30]] (* _Vincenzo Librandi_, Jan 15 2014 *)
%t A042151 LinearRecurrence[{0,98,0,-1},{1,2,97,196},30] (* _Harvey P. Dale_, Jul 04 2022 *)
%o A042151 (Magma) I:=[1,2,97,196]; [n le 4 select I[n] else 98*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Jan 15 2014
%Y A042151 Cf. A042150, A040575.
%K A042151 nonn,frac,easy
%O A042151 0,2
%A A042151 _N. J. A. Sloane_
%E A042151 More terms from _Colin Barker_, Dec 02 2013