A237810 - OEIS

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 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A237810

Primes p such that 2*p+1 and 2*p+7 are also prime.

2, 3, 5, 11, 23, 41, 53, 83, 113, 131, 173, 191, 251, 281, 293, 593, 641, 683, 743, 953, 1031, 1103, 1451, 1481, 1601, 2003, 2063, 2141, 2393, 2693, 2903, 3023, 3413, 3593, 3623, 3761, 3821, 3911, 4211, 4373, 4481, 4733, 4871, 5081, 5303, 5441, 5741, 5903

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

11 is in the sequence because 11, 2*11+1 = 23 and 2*11+7 = 29 are all prime.

MATHEMATICA

Select[Prime[Range[10000]], PrimeQ[2 # + 1]&&PrimeQ[2 # + 7]&] (* Vincenzo Librandi, Feb 15 2014 *)

PROG

(PARI) s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+7), s=concat(s, p))); s

(Magma) [p: p in PrimesUpTo(9200) | IsPrime(2*p+1) and IsPrime(2*p+7)]; // Vincenzo Librandi, Feb 15 2014