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A132090 Pi(pi(n)), where pi = A000720. 3
0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 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, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

R. Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) ~ n/log^2 n. - Charles R Greathouse IV, Aug 12 2014

PROG

(PARI) a(n)=primepi(primepi(n)) \\ Charles R Greathouse IV, Aug 12 2014

CROSSREFS

Cf. A000720, A006450, A000040, A000720, A137588.

Sequence in context: A240567 A067099 A098429 * A235043 A071538 A138194

Adjacent sequences:  A132087 A132088 A132089 * A132091 A132092 A132093

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Sep 03 2007

STATUS

approved

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Last modified December 19 08:59 EST 2014. Contains 252186 sequences.