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A023337 Numbers n such that n remains prime through 5 iterations of function f(x) = 3x + 8. 1
3181, 61981, 134291, 342821, 459091, 882451, 984931, 1016011, 1028471, 1181701, 1391561, 1897801, 2009311, 2272301, 2476421, 2769791, 3048041, 3085421, 3128821, 3207221, 3545111, 4092931, 4690591, 5015321, 5863651, 6027941, 6361351, 6796541 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 3*n+8, 9*n+32, 27*n+104, 81*n+320, 243*n+968 are primes. - Vincenzo Librandi, Aug 05 2010

LINKS

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

FORMULA

a(n) == 31 (mod 70). - John Cerkan, Oct 11 2016

MATHEMATICA

Select[Prime[Range[500000]], And@@PrimeQ[Rest[NestList[3#+8&, #, 5]]]&] (* Harvey P. Dale, Apr 07 2014 *)

PROG

(MAGMA) [n: n in [1..25000000] | IsPrime(n) and IsPrime(3*n+8) and IsPrime(9*n+32) and IsPrime(27*n+104) and IsPrime(81*n+320) and IsPrime(243*n+968)] // Vincenzo Librandi, Aug 05 2010

(PARI) is(n)=isprime(n) && isprime(3*n+8) && isprime(9*n+32) && isprime(27*n+104) && isprime(81*n+320) && isprime(243*n+968) \\ Charles R Greathouse IV, Oct 11 2016

CROSSREFS

Subsequence of A023210, A023248, and A023279, and A023309.

Sequence in context: A155484 A129472 A023309 * A236131 A205034 A205282

Adjacent sequences:  A023334 A023335 A023336 * A023338 A023339 A023340

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified June 17 17:12 EDT 2019. Contains 324196 sequences. (Running on oeis4.)