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A051507 Primes p such that p*q+2 is prime, where q is next prime after p. 9
3, 5, 7, 13, 19, 67, 149, 179, 229, 239, 241, 269, 277, 307, 313, 397, 401, 419, 439, 487, 569, 613, 643, 701, 823, 863, 887, 1051, 1289, 1319, 1489, 1609, 1693, 1783, 1873, 1999, 2143, 2239, 2309, 2423, 2539, 2549, 2593, 2617, 2729, 2753, 2819 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

MATHEMATICA

Prime[Select[Range[1000], PrimeQ[Prime[#]*Prime[# + 1] + 2] &]]

Reap[Do[If[PrimeQ[(p=Prime[k])*Prime[k+1]+2], Sow[p]], {k, 1, 430}]][[2, 1]] (* Zak Seidov, Dec 05 2010 *)

PROG

(Sage) A051507 = list(p for p in primes(10**4) if is_prime(p*next_prime(p)+2)) [D. S. McNeil, Dec 04 2010]

(PARI) p=2; forprime(q=3, 1e4, if(isprime(p*q+2), print1(p", ")); p=q) \\ Charles R Greathouse IV, May 01 2011

CROSSREFS

Cf. A048880.

Sequence in context: A154700 A187872 A180450 * A173145 A060274 A005235

Adjacent sequences:  A051504 A051505 A051506 * A051508 A051509 A051510

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified November 22 15:13 EST 2017. Contains 295089 sequences.