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A023335 Numbers n such that n remains prime through 5 iterations of function f(x) = 3x + 2. 1
10009, 575119, 724499, 1373819, 1725359, 3188569, 3715669, 4980499, 5939779, 9202199, 9565709, 13707469, 14483839, 14886829, 15412739, 16158589, 16740709, 18207349, 19429409, 22428209, 22602719, 22722419, 22749019, 22877119, 24171209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 3*n+2, 9*n+8, 27*n+26, 81*n+80 and 243*n+242 are primes. [From Vincenzo Librandi, Aug 04 2010]

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..180

MATHEMATICA

p5Q[n_]:=And@@PrimeQ[Rest[NestList[3#+2&, n, 5]]]; Select[ Prime[ Range[ 1600000]], p5Q] (* Harvey P. Dale, May 02 2011 *)

PROG

(MAGMA) [p: p in PrimesUpTo(25*10^6) | forall{k: k in [1..5] | IsPrime((p+1)*3^k-1)}];  //  Bruno Berselli, May 03 2011

CROSSREFS

Sequence in context: A173029 A256838 A176931 * A096211 A190149 A052095

Adjacent sequences:  A023332 A023333 A023334 * A023336 A023337 A023338

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified January 17 16:33 EST 2018. Contains 297822 sequences.