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 A042740 #29 Dec 26 2023 07:03:50 %S A042740 30,1801,108090,6487201,389340150,23366896201,1402403112210, %T A042740 84167553628801,5051455620840270,303171504804045001, %U A042740 18195341743863540330,1092023676136616464801,65539615909940851428390,3933468978272587702168201,236073678312265202981520450,14168354167714184766593395201 %N A042740 Numerators of continued fraction convergents to sqrt(901). %H A042740 Vincenzo Librandi, <a href="/A042740/b042740.txt">Table of n, a(n) for n = 0..200</a> %H A042740 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A042740 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (60,1). %F A042740 From _Philippe Deléham_, Nov 23 2008: (Start) %F A042740 a(n) = 60*a(n-1)+a(n-2) for n>1, a(0)=30, a(1)=1801. %F A042740 G.f.: (30+x)/(1-60*x-x^2). (End) %F A042740 E.g.f.: exp(30*x)*(30*cosh(sqrt(901)*x) + sqrt(901)*sinh(sqrt(901)*x)). - _Stefano Spezia_, May 14 2023 %t A042740 Numerator[Convergents[Sqrt[901], 30]] (* _Vincenzo Librandi_, Dec 03 2013 *) %Y A042740 Cf. A042741. %K A042740 nonn,frac,easy %O A042740 0,1 %A A042740 _N. J. A. Sloane_