OFFSET
1,2
COMMENTS
Denote this root as s_0, then Sum_{n>=1} log(n)/n^s > Sum_{n>=1} 1/n^s if and only if 1 < s < s_0; Sum_{n>=1} log(n)/n^s < Sum_{n>=1} 1/n^s if and only if s > s_0.
EXAMPLE
Uniquely for s_0 = 1.68041735920403754776..., we have Sum_{n>=1} log(n)/n^(s_0) = Sum_{n>=1} 1/n^(s_0).
MATHEMATICA
RealDigits[s /. FindRoot[Zeta[s] + Zeta'[s] == 0, {s, 2}, WorkingPrecision -> 120]][[1]] (* Amiram Eldar, Jun 25 2023 *)
PROG
(PARI) solve(x=1.5, 2, zeta(x)+zeta'(x))
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jianing Song, Feb 09 2023
STATUS
approved