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A023303 Numbers n such that n remains prime through 4 iterations of function f(x) = 2x + 3. 5
47, 67, 97, 137, 307, 1427, 2857, 6047, 6997, 9377, 12097, 16057, 24197, 32117, 35117, 36877, 44507, 46687, 54517, 55487, 64877, 71327, 71807, 76537, 89017, 92387, 94427, 100057, 132707, 142057, 153077, 160207, 184777, 186647, 194027, 200117, 205237 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes p such that (2p+3), (4p+9), (8p+21) and (16p+45) are also prime. - Vincenzo Librandi, Aug 04 2010

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Prime[Range[20000]], And@@PrimeQ[NestList[2#+3&, #, 4]]&] (* Harvey P. Dale, Aug 12 2012 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(300000) | IsPrime(p) and IsPrime(2*p+3) and IsPrime(4*p+9) and IsPrime(8*p+21) and IsPrime(16*p+45)] // Vincenzo Librandi, Aug 04 2010

CROSSREFS

Sequence in context: A099591 A046048 A163390 * A106874 A245745 A023331

Adjacent sequences:  A023300 A023301 A023302 * A023304 A023305 A023306

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified December 15 03:48 EST 2019. Contains 329990 sequences. (Running on oeis4.)