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A085341 Number of primes between sigma[n] and n. +0
7
0, 1, 0, 2, 0, 2, 0, 2, 2, 3, 0, 4, 0, 3, 3, 5, 0, 5, 0, 5, 3, 3, 0, 8, 2, 4, 3, 7, 0, 10, 0, 7, 4, 5, 4, 13, 0, 5, 4, 12, 0, 11, 0, 9, 7, 6, 0, 15, 1, 9, 5, 10, 0, 14, 4, 14, 6, 8, 0, 22, 0, 6, 9, 13, 5, 16, 0, 11, 5, 15, 0, 24, 0, 9, 9, 13, 3, 18, 0, 20, 8, 8, 0, 25, 5, 9, 7, 18, 0, 27, 5, 15, 7, 10 (list; graph; listen)
OFFSET

1,4

FORMULA

a(n)=Pi[sigma(n)]-Pi(n)=A000720[A000203(n)]-A000720(n)

EXAMPLE

n=12: sigma(n)=28, Pi(28)-Pi(12)=9-5=4

CROSSREFS

Cf. A000720, A000203, A070803, A070804, A085342-A085347.

Sequence in context: A076472 A161840 A140302 this_sequence A160812 A063918 A163169

Adjacent sequences: A085338 A085339 A085340 this_sequence A085342 A085343 A085344

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Jul 10 2003

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Last modified December 6 22:55 EST 2009. Contains 170429 sequences.


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