A064557 a(n) = # { p | A064553(k) = p prime and k <= n}.

0, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9

Offset

1,3

Comments

Primes occur in A064553 in natural order but less dense.

Links

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

Crossrefs

A000720, A064553.

Sequence in context: A235123 A242768 A365742 * A365737 A023967 A278163

Adjacent sequences: A064554 A064555 A064556 * A064558 A064559 A064560

Keyword

nonn

Author

Reinhard Zumkeller, Sep 21 2001

Status

approved