login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034785 a(n) = 2^(n-th prime). 33
4, 8, 32, 128, 2048, 8192, 131072, 524288, 8388608, 536870912, 2147483648, 137438953472, 2199023255552, 8796093022208, 140737488355328, 9007199254740992, 576460752303423488, 2305843009213693952 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..200

Index to divisibility sequences

FORMULA

From Amiram Eldar, Aug 11 2020: (Start)

a(n) = 2^A000040(n).

Sum_{n>=1} 1/a(n) = A051006. (End)

EXAMPLE

a(4) = 128 because the fourth prime number is 7 and 2^7 = 128.

MATHEMATICA

2^Prime@Range@40  (* Vladimir Joseph Stephan Orlovsky, Apr 11 2011 *)

PROG

(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

CROSSREFS

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

KEYWORD

easy,nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu)

EXTENSIONS

More terms from James A. Sellers, Feb 04 2000

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 8 01:41 EST 2021. Contains 341934 sequences. (Running on oeis4.)