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 A040090 #32 Aug 25 2025 11:14:06
%S A040090 10,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,
%T A040090 20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,
%U A040090 20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20
%N A040090 Continued fraction for sqrt(101).
%H A040090 <a href="/index/Con#confC">Index entries for continued fractions for constants</a>
%H A040090 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F A040090 From _Elmo R. Oliveira_, Feb 11 2024: (Start)
%F A040090 a(n) = 20 = A010859(n) for n >= 1.
%F A040090 G.f.: 10*(1+x)/(1-x).
%F A040090 E.g.f.: 20*exp(x) - 10.
%F A040090 a(n) = 10*A040000(n) = 5*A040002(n) = 2*A040020(n). (End)
%e A040090 10 + 1/(20 + 1/(20 + 1/(20 + 1/(20 + ...)))) = sqrt(101).
%p A040090 Digits := 200: convert(evalf(sqrt(101)),confrac,150,'cvgts'):
%t A040090 ContinuedFraction[Sqrt[101],300] (* _Vladimir Joseph Stephan Orlovsky_, Mar 10 2011*)
%t A040090 PadRight[{10},100,{20}] (* _Harvey P. Dale_, Apr 22 2022 *)
%Y A040090 Cf. A248803 (decimal expansion), A041180/A041181 (convergents).
%Y A040090 Cf. A040000, A040002, A040020.
%K A040090 nonn,cofr,easy,changed
%O A040090 0,1
%A A040090 _N. J. A. Sloane_