OFFSET
0,3
REFERENCES
F. Hirzebruch, Topological Methods in Algebraic Geometry, Springer, 3rd. ed., 1966; p. 12, Eq. 11.
FORMULA
G.f.: (x*sec(x)^2/tan(x))/2=sum{n>=0, a(n)*x^(2*n)} - Vladimir Kruchinin, Feb 04 2013
a(n) = numerator(Zeta(2*n)*(4^n-2)/Pi^(2*n)). - Peter Luschny, Aug 11 2014
EXAMPLE
1, 1/3, 7/45, 62/945, 127/4725, 146/13365, 2828954/638512875, 32764/18243225, 16931177/23260111875, 11499383114/38979295480125, ...
MAPLE
A171078 := n -> numer(Zeta(2*n)*(4^n-2)/Pi^(2*n));
seq(A171078(n), n=0..18); # Peter Luschny, Aug 11 2014
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, Sep 06 2010
STATUS
approved