login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A050921 Smallest prime of form n*2^m+1, m >= 0, or 0 if no prime exists. 10
2, 3, 7, 5, 11, 7, 29, 17, 19, 11, 23, 13, 53, 29, 31, 17, 137, 19, 1217, 41, 43, 23, 47, 97, 101, 53, 109, 29, 59, 31, 7937, 257, 67, 137, 71, 37, 149, 1217, 79, 41, 83, 43, 173, 89, 181, 47 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Primes arising from A040076 (or 0 if no such prime exists).

MATHEMATICA

Do[m = 0; While[ !PrimeQ[n*2^m + 1], m++ ]; Print[n*2^m + 1], {n, 1, 47} ]

CROSSREFS

Cf. A040076, A034694, A038699.

Sequence in context: A087572 A085107 A034694 * A087386 A110359 A092977

Adjacent sequences:  A050918 A050919 A050920 * A050922 A050923 A050924

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Dec 30 1999

EXTENSIONS

The next term (47*2^583 + 1) is too large to show.

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 08:49 EST 2012. Contains 205740 sequences.