

A066490


Number of primes of the form 4m+3 <= n.


5



0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13
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OFFSET

1,7


COMMENTS

Partial sums of A079261.  Reinhard Zumkeller, Feb 06 2014


LINKS

T. D. Noe, Table of n, a(n) for n=1..10000


MATHEMATICA

Table[ Length[ Select[ Union[ Table[ Prime[ PrimePi[i]], {i, 2, n}]], Mod[ #, 4] == 3 & ]], {n, 2, 100} ]


PROG

(PARI) for(n=1, 100, print1(sum(i=1, n, if((i*isprime(i)3)%4, 0, 1)), ", "))
(Haskell)
a066490 n = a066490_list !! (n1)
a066490_list = scanl1 (+) $ map a079261 [1..]
 Reinhard Zumkeller, Feb 06 2014


CROSSREFS

Cf. A066339.
Sequence in context: A000523 A124156 A072749 * A156685 A124230 A090973
Adjacent sequences: A066487 A066488 A066489 * A066491 A066492 A066493


KEYWORD

easy,nonn


AUTHOR

Robert G. Wilson v, Jan 03 2002


STATUS

approved



