A071839 Number of primes == 1 mod 8 <= n.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5

Offset

1,41

Links

Table of n, a(n) for n=1..105.

Prog

(PARI) for(n=1, 200, print1(sum(i=1, n, if((i*isprime(i)-1)%8, 0, 1)), ", "))

Crossrefs

Cf. A071840 (==3 mod 8), A071841 (==5 mod 8), A071842 (==7 mod 8).

Sequence in context: A339276 A343356 A242253 * A235044 A163857 A185715

Adjacent sequences: A071836 A071837 A071838 * A071840 A071841 A071842

Keyword

easy,nonn

Author

Benoit Cloitre, Jun 08 2002

Status

approved