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A045536 Primes p such that p+2 and 2p+1 are also prime. 13
3, 5, 11, 29, 41, 179, 191, 239, 281, 419, 431, 641, 659, 809, 1019, 1031, 1049, 1229, 1289, 1451, 1481, 1931, 2129, 2141, 2339, 2549, 2969, 3299, 3329, 3359, 3389, 3539, 3821, 3851, 4019, 4271, 4481, 5231, 5279, 5441, 5501, 5639, 5741, 5849, 6131 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A001359 and A005384. - Zak Seidov, Feb 28 2017

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

MAPLE

select(t -> isprime(t) and isprime(t+2) and isprime(2*t+1), [3, seq(t, t=5..10000, 6)]); # Robert Israel, Feb 28 2017

MATHEMATICA

Select[Prime[Range[1000]], PrimeQ[#+2] && PrimeQ[2#+1]&] (* Vladimir Joseph Stephan Orlovsky, Mar 30 2011*)

PROG

(MAGMA) [p: p in PrimesUpTo(6200) | IsPrime(p+2) and IsPrime(2*p+1)]; // Vincenzo Librandi, Apr 08 2013

(PARI) is(n)=isprime(n) && isprime(n+2) && isprime(2*n+1) \\ Charles R Greathouse IV, Feb 25 2014

CROSSREFS

Cf. A001359, A005384.

Sequence in context: A191025 A093706 A109945 * A019338 A046134 A177932

Adjacent sequences:  A045533 A045534 A045535 * A045537 A045538 A045539

KEYWORD

nonn,easy

AUTHOR

Thomas Kellar

EXTENSIONS

Corrected by Jud McCranie, Dec 30 2000

Name changed and incorrect comment and program removed by T. D. Noe, Aug 05 2010

STATUS

approved

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Last modified September 25 16:16 EDT 2017. Contains 292499 sequences.