OFFSET
1,2
COMMENTS
Conjecture: lim_{n->infinity} a(n)/n = C exists, with 5 < C < 6. [The conjecture was based on erroneous terms; C is about 2.05 (see graph). - Vaclav Kotesovec, Feb 18 2021]
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..10000
Vaclav Kotesovec, Plot of a(n)/n for n = 1..10000
EXAMPLE
zeta(1/2 + 15*i) = (0.1471...) + (0.7047...)*i; 0.1471... < 1 and 0.7047... < 1, hence 15 is in the sequence.
MATHEMATICA
Select[Range[100], Abs[Re[Zeta[1/2 + #*I]]] < 1 && Abs[Im[Zeta[1/2 + #*I]]] < 1 &] (* Vaclav Kotesovec, Feb 18 2021 *)
PROG
(PARI) isok(m) = my(x=zeta(1/2+m*I)); (abs(real(x)) < 1) && (abs(imag(x)) < 1); \\ Michel Marcus, Feb 18 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Aug 06 2002
EXTENSIONS
Corrected by Michel Marcus, Feb 18 2021
STATUS
approved