The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A175171 Primes p such that 3*2^p-1 is also prime 0
 2, 3, 7, 11, 43, 103, 827, 7559, 26459, 164987 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These are the primes in A002235. [From R. J. Mathar, May 02 2010] LINKS EXAMPLE For p=2, 3*2^2-1=11; p=3, 3*2^3-1=23; p=7, 3*2^7-1=383 PROG (MAGMA) [p: p in PrimesUpTo(7000) | IsPrime(3*2^p-1) ] CROSSREFS Sequence in context: A072534 A056292 A106125 * A073609 A267091 A053781 Adjacent sequences:  A175168 A175169 A175170 * A175172 A175173 A175174 KEYWORD nonn AUTHOR Vincenzo Librandi, Mar 09 2010 EXTENSIONS 3 more terms from R. J. Mathar, May 02 2010 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 December 1 20:01 EST 2021. Contains 349430 sequences. (Running on oeis4.)