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 A041371 #16 Jul 09 2025 00:43:12 %S A041371 1,7,197,1386,39005,274421,7722793,54333972,1529074009,10757852035, %T A041371 302748930989,2130000368958,59942759261813,421729315201649, %U A041371 11868363584907985,83500274409557544,2349876047052519217,16532632603777192063,465263588952813896981 %N A041371 Denominators of continued fraction convergents to sqrt(200). %H A041371 Vincenzo Librandi, <a href="/A041371/b041371.txt">Table of n, a(n) for n = 0..200</a> %H A041371 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,198,0,-1). %F A041371 G.f.: -(x^2-7*x-1) / ((x^2-14*x-1)*(x^2+14*x-1)). - _Colin Barker_, Nov 16 2013 %F A041371 a(n) = 198*a(n-2) - a(n-4). - _Vincenzo Librandi_, Dec 16 2013 %t A041371 Denominator[Convergents[Sqrt[200], 30]] (* _Vincenzo Librandi_, Dec 16 2013 *) %o A041371 (Magma) I:=[1,7,197,1386]; [n le 4 select I[n] else 198*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Dec 16 2013 %Y A041371 Cf. A041370, A040185. %K A041371 nonn,frac,easy %O A041371 0,2 %A A041371 _N. J. A. Sloane_ %E A041371 More terms from _Colin Barker_, Nov 16 2013