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A034785
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a(n) = 2^(n-th prime).
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33
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4, 8, 32, 128, 2048, 8192, 131072, 524288, 8388608, 536870912, 2147483648, 137438953472, 2199023255552, 8796093022208, 140737488355328, 9007199254740992, 576460752303423488, 2305843009213693952
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OFFSET
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1,1
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COMMENTS
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These are the "outputs" in Conway's PRIMEGAME (see A007542). - Alonso del Arte, Jan 03 2011
Multiplicative encoding of the n-th prime. - Daniel Forgues, Feb 26 2017
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index to divisibility sequences
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FORMULA
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From Amiram Eldar, Aug 11 2020: (Start)
a(n) = 2^A000040(n).
Sum_{n>=1} 1/a(n) = A051006. (End)
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EXAMPLE
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a(4) = 128 because the fourth prime number is 7 and 2^7 = 128.
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MATHEMATICA
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2^Prime@Range@40 (* Vladimir Joseph Stephan Orlovsky, Apr 11 2011 *)
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PROG
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(Haskell)
a034785 = (2 ^) . a000040
-- Reinhard Zumkeller, Feb 07 2015, Jan 24 2012
(PARI) a(n)=1<<prime(n) \\ Charles R Greathouse IV, Apr 07 2012
(MAGMA) [2^p: p in PrimesUpTo(100)]; // Vincenzo Librandi, Apr 29 2014
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CROSSREFS
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Cf. A000040, A000430, A051006, A073718 (2^(n-th composite)), A074736.
Sequence in context: A327493 A103970 A227295 * A247938 A072868 A075398
Adjacent sequences: A034782 A034783 A034784 * A034786 A034787 A034788
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KEYWORD
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easy,nonn
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AUTHOR
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Asher Auel (asher.auel(AT)reed.edu)
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EXTENSIONS
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More terms from James A. Sellers, Feb 04 2000
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STATUS
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approved
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