OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..100
Philippe Flajolet, Xavier Gourdon, and Philippe Dumas, Mellin transforms and asymptotics: harmonic sums, Special volume on mathematical analysis of algorithms. Theoret. Comput. Sci. 144 (1995), no. 1-2, 3-58.
EXAMPLE
1/sqrt(cosh(x)) = 1-(1/4)*x^2+(7/96)*x^4-(139/5760)*x^6+(5473/645120)*x^8-(51103/16588800)*x^10+...
MAPLE
a:= n-> denom(coeff(series(1/sqrt(cosh(x)), x, 2*n+1), x, 2*n)):
seq(a(n), n=0..19); # Alois P. Heinz, Sep 19 2023
MATHEMATICA
Denominator[Take[CoefficientList[Series[1/Sqrt[Cosh[x]], {x, 0, 40}], x], {1, -1, 2}]] (* Harvey P. Dale, Feb 04 2012 *)
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, May 05 2011
STATUS
approved