login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098471 Least k such that Mersenne-prime(n)*2^k+1 is prime (A000668(n)*2^k+1). 1
1, 2, 8, 2, 12, 864, 4, 10, 8, 72, 18, 38, 2144, 178, 472, 974, 2200, 8128, 4580, 822, 3600, 4100 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
MATHEMATICA
mexp = {the list in A000043}; f[n_] := Block[{k = 1, mp = 2^mexp[[n]] - 1}, While[ !PrimeQ[mp*2^k + 1] && k < 10000, k++ ]; If[k == 10000, 0, k]]; Do[ Print[ f[n]], {n, 22}] (* Robert G. Wilson v, Sep 13 2004 *)
CROSSREFS
Cf. A098472.
Sequence in context: A195844 A222828 A222842 * A341533 A341741 A074723
KEYWORD
nonn
AUTHOR
Pierre CAMI, Sep 09 2004
EXTENSIONS
a(18)-a(22) from Robert G. Wilson v, Sep 13 2004
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)