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 A054388 #14 Feb 16 2025 08:32:42 %S A054388 1,3,5,28,72,704,1664,2560,17408,311296,688128,3014656,6553600, %T A054388 56623104,121634816,520093696,369098752,7516192768,79456894976, %U A054388 111669149696,704374636544,5909874999296,824633720832,51677046505472 %N A054388 Denominators of coefficients of 1/2^(2n+1) in Newton's series for Pi. %H A054388 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiFormulas.html">Pi Formulas.</a> %F A054388 Pi = 3*sqrt(3)/4 + 24*(1/12 - sum(n >= 2, (2*n-2)!/((n-1)!^2*(2*n-3)*(2*n+1)*2^(4*n-2)))) (Newton) %Y A054388 Cf. A054387, A000796. %K A054388 nonn %O A054388 0,2 %A A054388 _Eric W. Weisstein_