|
%I #6 Dec 07 2016 10:24:05
%S 2,8,48,5760,80640,14515200,958003200,1394852659200,41845579776000,
%T 25609494822912000,4865804016353280000,528941518954168320000,
%U 1240896803466478878720000,1613165844506422542336000000,609776689223427721003008000000
%N Denominators of coefficients in expansion of 1/(1 + cos(sqrt(x))).
%C The numerators are the absolute values of the numbers at A089171.
%H Clark Kimberling, <a href="/A279109/b279109.txt">Table of n, a(n) for n = 0..1000</a>
%F (1/2)*A279110.
%e 1/2 + (1/8)x + (1/48)x^2 + (17/5760)x^3 + ... ; 1/2, 1/8, 1/48, 17/5760, 31/80640, ... = |A089171|/A279109.
%t z = 26; t = CoefficientList[Series[1/(1 + Cos[Sqrt[x]]), {x, 0, z}], x];
%t u = Numerator[t] (* A089171, unsigned *)
%t Denominator[t] (* A279109 *)
%Y Cf. A089171, A279110.
%K nonn,easy,frac
%O 0,1
%A _Clark Kimberling_, Dec 07 2016
|
