The OEIS is supported by the many generous donors to the OEIS 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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A089327 Smallest prime p such that 10*n*p +1 is prime. 0
 3, 2, 2, 7, 2, 3, 3, 3, 2, 7, 3, 2, 7, 2, 5, 13, 11, 3, 3, 2, 2, 3, 2, 5, 3, 2, 2, 31, 5, 2, 37, 2, 2, 3, 2, 5, 7, 2, 3, 3, 2, 11, 3, 2, 5, 3, 2, 7, 3, 11, 2, 13, 2, 3, 7, 5, 5, 3, 2, 2, 3, 3, 13, 7, 2, 2, 3, 2, 2, 31, 3, 3, 13, 2, 3, 3, 3, 3, 3, 2, 2, 7, 29, 3, 3, 2, 2, 31, 3, 2, 3, 17, 2, 7, 2, 5, 7, 11 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE 31,41,61,281, etc. are primes. MATHEMATICA With[{prs=Prime[Range[100]]}, Table[SelectFirst[prs, PrimeQ[10n*#+1]&], {n, 100}]] (* The program uses the SelectFirst function from Mathematica version 10 *) (* Harvey P. Dale, Apr 27 2015 *) CROSSREFS Sequence in context: A299778 A302248 A235773 * A280851 A279391 A237270 Adjacent sequences: A089324 A089325 A089326 * A089328 A089329 A089330 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 03 2003 EXTENSIONS More terms from David Wasserman, Sep 13 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 4 02:16 EST 2022. Contains 358544 sequences. (Running on oeis4.)