OFFSET
0,1
COMMENTS
Decimal expansion of 1/zeta(7), the inverse of A013665.
1/zeta(7) has no known closed-form formula like 1/zeta(2) = 6/Pi^2, 1/zeta(4) = 90/Pi^4 or 1/zeta(6) = 945/Pi^6.
1/zeta(7) is the probability that 7 randomly selected numbers will be coprime. - A.H.M. Smeets, Apr 13 2021
LINKS
Karl-Heinz Hofmann, Table of n, a(n) for n = 0..10000
Wikipedia, Riemann zeta function.
FORMULA
Equals 1/A013665.
Equals Sum_{k>=1} mobius(k) / k^7. - Sean A. Irvine, Aug 20 2021
Equals Product_{p prime} (1 - 1/p^7). - Amiram Eldar, Jun 01 2023
EXAMPLE
0.9917198558384443104281859314975506916499...
MATHEMATICA
RealDigits[1/Zeta[7], 10, 100][[1]] (* Amiram Eldar, Apr 13 2021 *)
PROG
(PARI) 1/zeta(7) \\ A.H.M. Smeets, Apr 13 2021
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Karl-Heinz Hofmann, Apr 12 2021
STATUS
approved