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!)
A191618 Least a such that (2^n+a)*2^n - 1 is prime. 11
0, 1, 1, 1, 2, 1, 11, 2, 2, 1, 13, 2, 4, 22, 2, 1, 2, 2, 43, 4, 2, 13, 2, 1, 13, 1, 2, 46, 8, 29, 83, 2, 8, 34, 1, 11, 19, 31, 25, 7, 38, 31, 31, 76, 52, 31, 43, 32, 13, 92, 2, 1, 59, 22, 1, 16, 19, 11, 16, 74, 8, 13, 8, 74, 2, 121, 20, 49, 85, 134, 116, 16 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Pierre CAMI, Table of n, a(n) for n = 1..5000

MATHEMATICA

Table[a = 0; While[! PrimeQ[(2^n + a)*2^n - 1], a++]; a, {n, 100}] (* T. D. Noe, Jun 11 2011 *)

CROSSREFS

Cf. A191617, A191619, A191620, A191621.

Sequence in context: A281350 A252158 A285996 * A306547 A143888 A016546

Adjacent sequences:  A191615 A191616 A191617 * A191619 A191620 A191621

KEYWORD

nonn

AUTHOR

Pierre CAMI, Jun 09 2011

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 June 13 05:37 EDT 2021. Contains 344981 sequences. (Running on oeis4.)