login
A390067
Decimal expansion of Sum_{k>=2} (-1)^k * zeta(k) / (4^k * (k+1)).
2
0, 3, 0, 2, 7, 9, 8, 9, 8, 9, 2, 3, 2, 4, 8, 3, 6, 1, 5, 6, 5, 0, 7, 1, 7, 8, 7, 5, 1, 3, 4, 9, 2, 1, 4, 8, 6, 4, 2, 0, 2, 0, 1, 4, 2, 9, 7, 3, 3, 2, 2, 2, 9, 0, 7, 7, 3, 2, 0, 4, 4, 3, 8, 6, 9, 1, 9, 3, 7, 7, 4, 7, 2, 1, 5, 6, 1, 0, 3, 8, 3, 2, 4, 3, 9, 5, 9, 1, 2, 4, 8, 9, 3, 7, 0, 4, 5, 5, 3, 4, 2, 2, 4, 4, 2, 2
OFFSET
0,2
REFERENCES
H. M. Srivastava and Junesang Choi, Zeta and q-Zeta Functions and Associated Series and Integrals, Elsevier Insights, 2011. See p. 339, eq. (666).
LINKS
Junesang Choi, The Catalan's constant and series involving the zeta function, Communications of the Korean Mathematical Society, Vol. 13, No. 2 (1998), pp. 435-443. See p. 441, eq. (3.6).
FORMULA
Equals 1 + gamma/8 - G/Pi - log(2 * Pi * A^9 / Gamma(1/4)^2)/2, where gamma is Euler's constant (A001620), G is Catalan's constant (A006752), and A is the Glaisher-Kinkelin constant (A074962).
EXAMPLE
0.03027989892324836156507178751349214864202014297332...
MATHEMATICA
RealDigits[1 + EulerGamma/8 - Catalan/Pi - Log[2*Pi]/2 - 9*Log[Glaisher]/2 + Log[Gamma[1/4]], 10, 120, -1][[1]]
PROG
(PARI) 5/8 + Euler/8 - Catalan/Pi - log(2*Pi)/2 + 9*zeta'(-1)/2 + log(gamma(1/4))
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Oct 23 2025
STATUS
approved