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!)
A057188 Numbers n such that (22^n+1)/23 is a prime. 14

%I

%S 3,5,13,43,79,101,107,227,353,7393,50287

%N Numbers n such that (22^n+1)/23 is a prime.

%C Some of the larger terms may only correspond to probable primes.

%C a(12) > 10^5 - _Robert Price_, Jun 02 2013

%H H. Dubner and T. Granlund, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/DUBNER/dubner.html">Primes of the Form (b^n+1)/(b+1)</a>, J. Integer Sequences, 3 (2000), #P00.2.7.

%o (PARI) isok(n) = (denominator(p=(22^n+1)/23)==1) && isprime(p); \\ _Michel Marcus_, Oct 30 2017

%K nonn,more

%O 1,1

%A _N. J. A. Sloane_, Sep 15 2000

%E a(11) from _Robert Price_, Jun 02 2013

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 September 19 08:05 EDT 2021. Contains 347556 sequences. (Running on oeis4.)