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
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=5) on p. 21.
FORMULA
P_{3,2}(5) = P(5) - 1/3^5 - P_{3,1}(5).
EXAMPLE
0.0315771357190039419560337803437163963477729963832486145790258341228297557...
PROG
(PARI) s=0; forprimestep(p=2, 1e8, 3, s+=1./p^4); s \\ For illustration: using primes up to 10^N gives about 3N+2 (= 26 for N=8) correct digits.
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
M. F. Hasler, Apr 22 2021
STATUS
approved