OFFSET
0,1
COMMENTS
Appears in lattice sums like A088537.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..10000
Wikipedia, Dirichlet beta function
FORMULA
Equals (zeta(1/2,1/4) - zeta(1/2,3/4))/2 where zeta(.,.) is the Hurwitz zeta-function.
EXAMPLE
Equals 0.66769145718960917665869...
MAPLE
DirichletBeta := proc(s) (Zeta(0, s, 1/4)-Zeta(0, s, 3/4))/4^s ; end proc:
x := evalf(DirichletBeta(1/2)) ;
MATHEMATICA
RealDigits[ DirichletBeta[1/2], 10, 75] // First (* Jean-François Alcover, Feb 20 2013, updated Mar 14 2018 *)
PROG
(PARI) zetahurwitz(1/2, 1/4)/2 - zetahurwitz(1/2, 3/4)/2 \\ Charles R Greathouse IV, Jan 31 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
R. J. Mathar, Sep 09 2011
STATUS
approved