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!)
A050858 Numbers n such that 213*2^n-1 is prime. 0
4, 10, 19, 30, 36, 47, 80, 82, 92, 100, 103, 114, 126, 140, 144, 152, 170, 210, 264, 514, 726, 967, 1662, 2423, 3116, 3974, 4396, 5735, 6680, 6707, 9947, 23814, 24330, 43074, 43775, 77922, 98179, 120362, 171154, 303670, 709727, 760942 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..42.

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

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

Kosmaj, Riesel list k<300.

PROG

(PARI) is(n)=ispseudoprime(213*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A029714 A348239 A062198 * A173248 A267882 A238705

Adjacent sequences:  A050855 A050856 A050857 * A050859 A050860 A050861

KEYWORD

hard,nonn

AUTHOR

N. J. A. Sloane, Dec 29 1999

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

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 October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)