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A237811 Primes p such that 2*p+1 and 2*p+9 are also prime. 5
2, 5, 11, 29, 131, 179, 239, 281, 359, 491, 641, 659, 719, 761, 809, 911, 1229, 1439, 1481, 1811, 2549, 2699, 2819, 3299, 3449, 3491, 4211, 4349, 4481, 5051, 5279, 5441, 5639, 5741, 6101, 6269, 6449, 6581, 6899, 7121, 7211, 7541, 7649, 7691, 8111, 8741, 8951 (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+9 = 31 are all prime.

MATHEMATICA

Select[Prime[Range[10000]], PrimeQ[2 # + 1]&&PrimeQ[2 # + 9]&] (* Vincenzo Librandi, Feb 15 2014 *)

PROG

(PARI) s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+9), s=concat(s, p))); s

(Magma) [p: p in PrimesUpTo(9200) | IsPrime(2*p+1) and IsPrime(2*p+9)]; // Vincenzo Librandi, Feb 15 2014

CROSSREFS

Cf. A126107, A237810, A237812, A237813, A237814.

Sequence in context: A014211 A160911 A092764 * A264771 A176637 A272675

Adjacent sequences:  A237808 A237809 A237810 * A237812 A237813 A237814

KEYWORD

nonn,easy

AUTHOR

Colin Barker, Feb 13 2014

STATUS

approved

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Last modified October 3 14:05 EDT 2022. Contains 357237 sequences. (Running on oeis4.)