%I #13 Feb 23 2013 22:34:07
%S 1,3,5,28,72,704,1664,2560,17408,311296,688128,3014656,6553600,
%T 56623104,121634816,520093696,369098752,7516192768,79456894976,
%U 111669149696,704374636544,5909874999296,824633720832,51677046505472
%N Denominators of coefficients of 1/2^(2n+1) in Newton's series for Pi.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PiFormulas.html">Pi Formulas.</a>
%F 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 Cf. A054387, A000796.
%K nonn
%O 0,2
%A _Eric W. Weisstein_