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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057184 Numbers n such that (18^n + 1)/19 is a prime. 15
3, 7, 23, 73, 733, 941, 1097, 1933, 4651, 481147 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.

H. Lifchitz, Mersenne and Fermat primes field

Paul Bourdelais,A Generalized Repunit Conjecture

CROSSREFS

Sequence in context: A191638 A148704 A283109 * A148705 A148706 A148707

Adjacent sequences:  A057181 A057182 A057183 * A057185 A057186 A057187

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 15 2000

EXTENSIONS

a(10) = 481147 corresponds to a probable prime, which was found using PFGW v3.3.1. - Paul Bourdelais, Jul 27 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 December 12 07:00 EST 2019. Contains 329948 sequences. (Running on oeis4.)