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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A134303 Least k such that k*2^n*(k*2^n-1)-1 is prime. 3
2, 1, 2, 1, 1, 3, 4, 2, 1, 1, 19, 15, 13, 9, 8, 4, 2, 1, 35, 29, 31, 26, 13, 12, 6, 3, 27, 25, 31, 20, 10, 5, 32, 16, 8, 4, 2, 1, 17, 9, 16, 8, 4, 2, 1, 5, 8, 4, 2, 1, 64, 32, 16, 8, 4, 2, 1, 29, 120, 60, 30, 15, 35, 41, 37, 60, 30, 15 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Pierre CAMI, Table of n, a(n) for n = 1..2500

MAPLE

A134303 := proc(n)

    for k from 1 do

        k*2^n*(k*2^n-1)-1 ;

        if isprime(%) then

            return k;

        end if;

    end do:

end proc:

seq(A134303(n), n=1..80) ; # R. J. Mathar, Nov 30 2011

MATHEMATICA

lk[n_]:=Module[{k=1, n2=2^n}, While[!PrimeQ[k*n2(k n2-1)-1], k++]; k]; Array[ lk, 70] (* Harvey P. Dale, Sep 29 2017 *)

CROSSREFS

Cf. A134304, A134305.

Sequence in context: A205810 A139368 A266506 * A078997 A024680 A083531

Adjacent sequences:  A134300 A134301 A134302 * A134304 A134305 A134306

KEYWORD

nonn

AUTHOR

Pierre CAMI, Oct 19 2007

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 August 23 01:10 EDT 2019. Contains 326211 sequences. (Running on oeis4.)