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 A325159 #36 May 12 2019 02:27:20 %S A325159 1,2,7,14,21,57,113,226,339,565,1130,2147,4181,8249,32763,33215,99532, %T A325159 199064,364913,995207,1725033,3450066,5175099,15160384,25510582, %U A325159 52746197,131002976,209259755,340262731,811528438,1963319607,3926639214,6701487259,13402974518,20104461777 %N A325159 Denominators of convergents to Pi using best rational approximation whose denominator is between consecutive powers of 2: [2^n, 2^(n+1)-1], where n = 0, 1, 2, ... %H A325159 Serguei Zolotov, <a href="/A325159/b325159.txt">Table of n, a(n) for n = 0..1023</a> %H A325159 E. Charrier and L. Buzer, <a href="https://doi.org/10.1016/j.dam.2009.03.005">Approximating a real number by a rational number with a limited denominator: A geometric approach</a>, Discrete Applied Mathematics, Volume 157, Issue 16, 28 August 2009, Pages 3473-3484. %H A325159 Serguei Zolotov, <a href="/A325159/a325159.py.txt">Python program to calculate b-file</a> %e A325159 The convergents are 3/1, 6/2, 22/7, 44/14, 66/21, 179/57, 355/113, 710/226, 1065/339, 1775/565, 3550/1130, 6745/2147, 13135/4181, 25915/8249, 102928/32763, ... = A325158/A325159. %Y A325159 Cf. A325158 (numerators), A002485. %K A325159 nonn %O A325159 0,2 %A A325159 _Serguei Zolotov_, Apr 04 2019