OFFSET
0,1
LINKS
R. J. Mathar, Hardy-Littlewood constants embedded into infinite products..., arXiv:0903.2514.
FORMULA
Equals product_{n >= 2} (1-n^(-4)).
Equals A156648/4.
Equals exp(Sum_{j>=1} (1 - zeta(4*j))/j). - Vaclav Kotesovec, Apr 27 2020
Equals 1/(2*Gamma(2-i)*Gamma(2+i)). - Amiram Eldar, May 28 2021
EXAMPLE
0.91901947759...
MAPLE
sinh(Pi)/4/Pi; evalf(%) ;
MATHEMATICA
RealDigits[Sinh[Pi]/(4Pi), 10, 120][[1]] (* Harvey P. Dale, Feb 11 2023 *)
PROG
(PARI) exp(suminf(j=1, (1 - zeta(4*j))/j)) \\ Vaclav Kotesovec, Apr 27 2020
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Jul 26 2010
STATUS
approved