This site is supported by donations to The OEIS Foundation.

 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!)
 A215714 Sophie Germain primes q such that q^2 + q + 41 is prime. 1
 2, 3, 5, 11, 23, 29, 53, 83, 113, 131, 179, 191, 233, 281, 293, 359, 419, 509, 641, 653, 659, 683, 719, 743, 809, 911, 953, 1013, 1019, 1103, 1289, 1439, 1481, 1511, 1601, 1733, 1811, 1901, 1931, 2003, 2039, 2339, 2393, 2549, 2693, 2903, 2939, 3023, 3299, 3329 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS By definition, p = 2 * q + 1 is prime and (p^2 + 163)/4 = q^2 + q + 41 is also prime. LINKS Pierre CAMI, Table of n, a(n) for n = 1..10000 FORMULA A005384 INTERSECT A056561. - R. J. Mathar, Aug 23 2012 EXAMPLE 29 is in the sequence because not only is 2 * 29 + 1 = 59 a prime, so is 29^2 + 29 + 41 = 911. MATHEMATICA Select[Prime[Range[500]], PrimeQ[2# + 1] && PrimeQ[#^2 + # + 41] &] (* Alonso del Arte, Aug 21 2012 *) CROSSREFS Cf. A005384, A005846. Sequence in context: A005384 A118571 A118504 * A038905 A019405 A079848 Adjacent sequences:  A215711 A215712 A215713 * A215715 A215716 A215717 KEYWORD nonn AUTHOR Pierre CAMI, Aug 21 2012 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 7 09:33 EST 2019. Contains 329843 sequences. (Running on oeis4.)