OFFSET
0,1
FORMULA
Equals (cosh(sqrt((5 - sqrt(5))/2)*Pi) + sin(sqrt(5)*Pi/2)) * (cosh(sqrt((5 + sqrt(5))/2)*Pi) - sin(sqrt(5)*Pi/2)) / (40*Pi^4).
Equals exp(Sum_{j>=1} (1 - zeta(10*j))/j).
EXAMPLE
0.99900544248098947527378453585422724586059097385364736908229...
MAPLE
evalf((cosh(sqrt((5 - sqrt(5))/2)*Pi) + sin(sqrt(5)*Pi/2)) * (cosh(sqrt((5 + sqrt(5))/2)*Pi) - sin(sqrt(5)*Pi/2)) / (40*Pi^4), 100);
MATHEMATICA
RealDigits[(Cosh[Sqrt[(5 - Sqrt[5])/2]*Pi] + Sin[Sqrt[5]*Pi/2]) * (Cosh[Sqrt[(5 + Sqrt[5])/2]*Pi] - Sin[Sqrt[5]*Pi/2]) / (40*Pi^4), 10, 100][[1]]
PROG
(PARI) exp(suminf(j=1, (1 - zeta(10*j))/j))
(PARI) prodinf(n=2, 1-1/n^10) \\ Michel Marcus, Dec 15 2020
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Vaclav Kotesovec, Dec 15 2020
STATUS
approved