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 A096954 #17 Feb 23 2023 11:28:35 %S A096954 951,1339849258,9569810428334921,19132121777295048135244, %T A096954 81963468350564671450762204559,1287504688596138051498743351405666674, %U A096954 23901655485793371607250742363386659018053931 %N A096954 Numerators of rational approximation to Pi/4 from Machins's formula. %C A096954 Machin's formula: Pi/4 = 4*arctan(1/5) - arctan(1/239). %C A096954 Denominators are given in A096955. %D A096954 W. Walter, Analysis I (in German), Springer, 3. Auflage, 1992; p. 216. %H A096954 Wolfdieter Lang, <a href="/A096954/a096954.txt">More comments</a>. %H A096954 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MachinsFormula.html">Machin's Formula</a>. %F A096954 a(n)=numerator(M(n)), with M(n)=4*arctan(1/5, n) - arctan(1/239, n) with arctan(x, n):=sum((((-1)^k)*x^(2k+1))/(2*k+1), k=0..n). %e A096954 a(2)/A096955(2) = 9569810428334921/12184551018734375 = .78540... %Y A096954 Cf. A003881, A096955. %K A096954 nonn,frac,easy %O A096954 0,1 %A A096954 _Wolfdieter Lang_, Jul 23 2004