login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A343613
Decimal expansion of P_{3,2}(3) = Sum 1/p^3 over primes == 2 (mod 3).
4
1, 3, 4, 1, 2, 5, 1, 7, 8, 9, 1, 5, 4, 6, 3, 5, 4, 0, 4, 2, 8, 5, 9, 9, 3, 2, 9, 9, 9, 9, 4, 3, 1, 1, 9, 8, 9, 9, 5, 8, 7, 9, 9, 1, 9, 7, 5, 2, 1, 6, 8, 3, 3, 7, 3, 7, 0, 5, 9, 9, 1, 0, 6, 1, 5, 3, 8, 5, 3, 3, 4, 9, 9, 5, 6, 0, 4, 7, 9, 3, 7, 6, 7, 1, 5, 2, 8, 6, 5, 3, 7, 4, 0, 4, 0, 3, 4, 4, 4, 3, 3, 6, 7, 8, 6
OFFSET
0,2
COMMENTS
The prime zeta modulo function P_{m,r}(s) = Sum_{primes p == r (mod m)} 1/p^s generalizes the prime zeta function P(s) = Sum_{primes p} 1/p^s.
LINKS
Jean-François Alcover, Table of n, a(n) for n = 0..1006
R. J. Mathar, Table of Dirichlet L-series and Prime Zeta Modulo Functions for Small Moduli, arXiv:1008.2547 [math.NT], 2010-2015, value P(m=3, n=2, s=3) on p. 21.
FORMULA
P_{3,2}(3) = P(3) - 1/3^3 - P_{3,1}(3) = A085541 - A021031 - A175645.
EXAMPLE
0.134125178915463540428599329999431198995879919752168337370599106153853349956...
PROG
(PARI) s=0; forprimestep(p=2, 1e8, 3, s+=1./p^3); s \\ For illustration: using primes up to 10^N gives about 2N+2 (= 18 for N=8) correct digits.
(PARI) A343613_upto(N=100)={localprec(N+5); digits((PrimeZeta32(3)+1)\.1^N)[^1]} \\ see A343612 for the function PrimeZeta32.
CROSSREFS
Cf. A003627 (primes 3k-1), A085541 (PrimeZeta(3)), A021031 (1/27).
Cf. A175645 (same for p==1 (mod 3)), A086033 (for primes 4k+1), A085992 (for primes 4k+3), A343612 - A343619 (P_{3,2}(2..9): same for 1/p^2, ..., 1/p^9).
Sequence in context: A076942 A205127 A360407 * A333454 A021971 A260822
KEYWORD
nonn,cons
AUTHOR
M. F. Hasler, Apr 22 2021
STATUS
approved