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A237810 Primes p such that 2*p+1 and 2*p+7 are also prime. 5
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

CROSSREFS

Cf. A126107, A237811, A237812, A237813, A237814.

Sequence in context: A019405 A079848 A329749 * A073434 A109551 A326393

Adjacent sequences:  A237807 A237808 A237809 * A237811 A237812 A237813

KEYWORD

nonn,easy

AUTHOR

Colin Barker, Feb 13 2014

STATUS

approved

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Last modified September 28 17:45 EDT 2022. Contains 357080 sequences. (Running on oeis4.)