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A023241 Primes that remain prime through 2 iterations of function f(x) = x + 6. 9
5, 7, 11, 17, 31, 41, 47, 61, 67, 97, 101, 151, 167, 227, 251, 257, 271, 347, 367, 557, 587, 601, 607, 641, 647, 727, 941, 971, 1091, 1097, 1117, 1181, 1217, 1277, 1291, 1361, 1427, 1447, 1481, 1487, 1601, 1607, 1657, 1741, 1747, 1777, 1861, 1867, 1901, 1987 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes p such that p+6 and p+12 are also primes.

LINKS

Lei Zhou, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Prime Triplet

MATHEMATICA

triq[p_] := And[PrimeQ[p + 6], PrimeQ[p + 12]]; Select[Prime[Range[1000]], triq]  (* Ben Branman, Sep 03 2012 *)

nrpQ[n_]:=AllTrue[Rest[NestList[#+6&, n, 2]], PrimeQ]; Select[Prime[Range[ 300]], nrpQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jan 27 2021 *)

PROG

(MAGMA) [n: n in [0..1000] | IsPrime(n) and IsPrime(n+6) and IsPrime(n+12)] // Vincenzo Librandi, Nov 20 2010

CROSSREFS

Sequence in context: A145987 A060449 A046140 * A174357 A134572 A106954

Adjacent sequences:  A023238 A023239 A023240 * A023242 A023243 A023244

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 14 09:34 EDT 2021. Contains 343879 sequences. (Running on oeis4.)