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A023317 Numbers n such that n remains prime through 4 iterations of function f(x) = 6x + 5. 2
11, 13, 83, 151, 317, 373, 1721, 3529, 4153, 4243, 4637, 4783, 5209, 5849, 5923, 6661, 8431, 10903, 11329, 14519, 16183, 16979, 20149, 26669, 27509, 27827, 29873, 29947, 32987, 33637, 33937, 34919, 35099, 35543, 36277, 36691, 38069, 38461, 41651, 47407 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 6*n+5, 36*n+35, 216*n+215 and 1296*n+1295 are primes. - Vincenzo Librandi, Aug 04 2010

LINKS

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

MATHEMATICA

if4Q[n_]:=AllTrue[Rest[NestList[6#+5&, n, 4]], PrimeQ]; Select[Prime[ Range[ 5000]], if4Q] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 10 2018 *)

PROG

(MAGMA) [n: n in [1..1000000] | IsPrime(n) and IsPrime(6*n+5) and IsPrime(36*n+35) and IsPrime(216*n+215) and IsPrime(1296*n+1295)] // Vincenzo Librandi, Aug 04 2010

CROSSREFS

Subsequence of A023221, A023257, A023288, and A059325.

Sequence in context: A116436 A185240 A056446 * A056436 A334930 A089824

Adjacent sequences:  A023314 A023315 A023316 * A023318 A023319 A023320

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified August 12 16:40 EDT 2020. Contains 336439 sequences. (Running on oeis4.)