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A023349 Numbers n such that n remains prime through 5 iterations of function f(x) = 8x + 5. 1
109891, 324763, 852367, 3371527, 3557797, 4448701, 4471549, 5304661, 5616679, 5688919, 5727349, 7766659, 8028109, 8554999, 9034723, 10867099, 11146987, 12396487, 12926401, 14186611, 18274513, 19251517, 20882713, 21810493, 23953921 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 8*n+5, 64*n+45, 512*n+365, 4096*n+2925 and 32768*n+23405 are primes. - Vincenzo Librandi, Aug 05 2010

LINKS

John Cerkan, Table of n, a(n) for n = 1..10000

FORMULA

a(n) == 19 (mod 42). - John Cerkan, Nov 06 2016

MATHEMATICA

p5Q[n_]:=And@@PrimeQ/@NestList[8#+5&, n, 5]; Parallelize[Select[Prime[Range[1510000]], p5Q]] (* Harvey P. Dale, Feb 22 2011 *)

PROG

(MAGMA) [n: n in [1..19000000] | IsPrime(n) and IsPrime(8*n+5) and IsPrime(64*n+45) and IsPrime(512*n+365) and IsPrime(4096*n+2925) and IsPrime(32768*n+23405)] // Vincenzo Librandi, Aug 05 2010

CROSSREFS

Subsequence of A023230, A023262, A023293, A023321, and A105133.

Sequence in context: A238061 A111888 A183770 * A138722 A122240 A250591

Adjacent sequences:  A023346 A023347 A023348 * A023350 A023351 A023352

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified April 23 06:08 EDT 2019. Contains 322381 sequences. (Running on oeis4.)