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Search: id:A065515
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| A065515 |
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Number of prime powers <= n. |
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+0
9
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| 1, 2, 3, 4, 5, 5, 6, 7, 8, 8, 9, 9, 10, 10, 10, 11, 12, 12, 13, 13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 19, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 22, 22, 22, 22, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 29, 30, 30, 31
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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a(n) > pi(n) = A000720(n).
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LINKS
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R. Zumkeller, Table of n, a(n) for n = 1..10000
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FORMULA
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Partial sums of A010055. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 22 2009]
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EXAMPLE
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There are 9 prime powers <= 12: 1=2^0, 2, 3, 4=2^2, 5, 7, 8=2^3, 9=3^2 and 11, so a(12) = 9.
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CROSSREFS
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Cf. A000040, A000961, A000720.
A025528 = a(n) - 1.
Sequence in context: A064067 A020892 A138366 this_sequence A070545 A091863 A163296
Adjacent sequences: A065512 A065513 A065514 this_sequence A065516 A065517 A065518
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KEYWORD
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nice,nonn,new
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 27 2001
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