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Search: id:A086690
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| A086690 |
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Number of primes < 2^prime(n). |
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+0
2
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| 2, 4, 11, 31, 309, 1028, 12251, 43390, 564163, 28192750, 105097565, 5586502348, 80316571436, 305761713237, 4461632979717, 252252704148404, 14458792895301660, 55890484045084135, 3249254387052557215, 48995571600129458363, 190499823401327905601
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Tomas Oliveira e Silva, Tables of values of pi(x) and of pi2(x)
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EXAMPLE
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There are 11 primes < 2^5
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MATHEMATICA
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Table[ PrimePi[ 2^Prime[n]], {n, 1, 14}]
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PROGRAM
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(PARI) primesless2p(n) = \primes less than 2^p { forprime(x=2, n, y=pi(2^x); print1(y", "); ); print(); print(sr) } pi(n) = { c=0; forprime(x=2, n, c++); return(c) }
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CROSSREFS
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Cf. A007053.
Sequence in context: A123427 A123421 A123430 this_sequence A059305 A120848 A135339
Adjacent sequences: A086687 A086688 A086689 this_sequence A086691 A086692 A086693
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KEYWORD
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nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)gmail.com), Jul 28 2003
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EXTENSIONS
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Extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 30 2003
Revised by Max Alekseyev (maxale(AT)gmail.com), Jul 20 2007
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