This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A087886 Numbers n such that 29^n + 2 is prime. 7
 0, 1, 3, 63, 87, 189, 239, 605, 2099, 3667, 5029, 20025, 45285, 99167 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS After 0, all terms are odd. [Bruno Berselli, Oct 02 2014] LINKS Henri & Renaud Lifchitz, PRP Records. EXAMPLE a(1) = 1 is a member because 29^1 + 2 = 31 is prime. 29^3+2 = 24391 is prime, so 3 is in the sequence. PROG (PARI) for( n = 0, 239, if( isprime( 29^n +2), print( n), )) CROSSREFS Cf. A051783, n such that 3^n +2 is prime. Cf. A087885, 5^n +2 is prime. Sequence in context: A144422 A135444 A182468 * A123754 A048354 A046181 Adjacent sequences:  A087883 A087884 A087885 * A087887 A087888 A087889 KEYWORD nonn,more AUTHOR Donald S. McDonald, Oct 13 2003 EXTENSIONS a(8) from Mark Hudson (mrmarkhudson(AT)hotmail.com), Sep 07 2004 a(9) - a(11), corresponding to probable primes, from Ryan Propper, Jul 03 2005 Edited by T. D. Noe, Oct 30 2008 a(12) from Ray Chandler, Aug 01 2011 a(13) from Ray Chandler, Aug 02 2011 a(14) from Ray Chandler, Aug 08 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.

Last modified January 18 13:01 EST 2019. Contains 319271 sequences. (Running on oeis4.)