A157042 Primes p such that 6p-7, 6p-5, 6p-1 are all prime.

2, 3, 19, 53, 59, 239, 269, 313, 379, 449, 613, 823, 829, 1373, 1723, 2699, 4019, 5209, 5233, 5923, 6079, 6389, 8069, 8663, 8849, 8933, 11239, 11369, 12269, 12503, 13669, 13879, 14543, 15263, 15583, 15649, 16229, 16453, 16619, 17333, 18049, 18583

Offset

1,1

Links

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

Example

For p=2, (5,7,11 prime); p=3, (11,13,17 prime); p=19, (107,109,113);

Maple

a := proc (n) if isprime(6*ithprime(n)-7) = true and isprime(6*ithprime(n)-5) = true and isprime(6*ithprime(n)-1) = true then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 2200); # Emeric Deutsch, Mar 01 2009

Mathematica

Select[Prime@Range@20000, PrimeQ[6 # - 1] && PrimeQ[6 # - 7] && PrimeQ[6 # - 5] &] (* Vincenzo Librandi, Sep 11 2013 *)
Select[Prime[Range[2200]], AllTrue[6#-{1, 5, 7}, PrimeQ]&] (* Harvey P. Dale, Mar 04 2022 *)

Prog

(Magma) [p: p in PrimesUpTo(20000) | IsPrime(6*p-7) and IsPrime(6*p-5) and IsPrime(6*p-1)]; // Vincenzo Librandi, Sep 11 2013

Crossrefs

Cf. A157043.

Sequence in context: A289860 A248702 A171149 * A128968 A153409 A143893

Adjacent sequences: A157039 A157040 A157041 * A157043 A157044 A157045

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 22 2009

Extensions

Corrected (269 added) and extended by Emeric Deutsch, Mar 01 2009

Status

approved