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 A123626 #14 May 05 2025 23:41:05 %S A123626 1,5,102,2970,16450,997220,18268740,37403100,2539082700,23305436, %T A123626 141249408300,97836438700 %N A123626 Denominators of the convergents of the continued fraction for Pi/sqrt(3) using the classical continued fraction for arctan(x). %C A123626 It turns out that A123625(n)/a(n) are good approximations to Pi/sqrt(3). In a similar vein R. Apery discovered in 1978 an infinite sequence of good quality approximations to Pi^2. But for Pi itself, it was not until 1993 that Hata succeeded in doing so! %H A123626 Frits Beukers, <a href="http://www.nieuwarchief.nl/serie5/pdf/naw5-2000-01-4-372.pdf">A rational approach to Pi</a>, NAW 5/1 nr.4, december 2000, p. 378. %F A123626 Convergents are given by Pi/sqrt(3) = 2/(1+p_1/(3+p_2/(5+p_3/(7+p_4/(9+...))))) where p_i = i^2/3. %Y A123626 Cf. A093602, A123625. %K A123626 frac,nonn,more %O A123626 1,2 %A A123626 _Benoit Cloitre_, Oct 03 2006