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

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A050528 Primes of the form 9*2^n+1. 2
19, 37, 73, 577, 1153, 18433, 147457, 1179649, 77309411329, 39582418599937, 79164837199873, 83010348331692982273, 332041393326771929089, 1328165573307087716353, 21760664753063325144711169, 196002643346460554954903773880698489798657 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..25

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

MAPLE

A050528:=n->`if`(isprime(9*2^n+1), 9*2^n+1, NULL): seq(A050528(n), n=1..200); # Wesley Ivan Hurt, Aug 09 2014

MATHEMATICA

Select[9*2^Range[150]+1, PrimeQ] (* Harvey P. Dale, Aug 08 2014 *)

PROG

(MAGMA) [a: n in [0..150] | IsPrime(a) where a is (9*2^n+1) ]; // Vincenzo Librandi, Aug 09 2014

CROSSREFS

For more terms see A002256.

Sequence in context: A158293 A107579 A245381 * A053685 A244111 A136063

Adjacent sequences:  A050525 A050526 A050527 * A050529 A050530 A050531

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 29 1999

STATUS

approved

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

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

Last modified October 2 04:45 EDT 2014. Contains 247527 sequences.