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 A040402 #18 Jul 08 2025 23:14:06
%S A040402 20,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,
%T A040402 40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,
%U A040402 40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1,40,1,1,3,4,3,1,1
%N A040402 Continued fraction for sqrt(423).
%H A040402 <a href="/index/Con#confC">Index entries for continued fractions for constants</a>
%H A040402 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 1).
%p A040402 with(numtheory): Digits := 300: convert(evalf(sqrt(423)),confrac);
%t A040402 ContinuedFraction[Sqrt[423],100] (* or *) PadRight[{20},100,{40,1,1,3,4,3,1,1}] (* _Harvey P. Dale_, Jan 03 2023 *)
%K A040402 nonn,cofr,easy
%O A040402 0,1
%A A040402 _N. J. A. Sloane_