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A023291
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Numbers n such that n remains prime through 3 iterations of function f(x) = 8x + 1.
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0
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2, 1487, 2207, 2927, 8807, 11117, 16187, 17657, 26357, 44927, 45377, 48497, 91757, 110237, 117167, 122327, 125387, 126107, 145007, 170927, 174527, 190787, 193847, 203897, 230567, 244247, 246017, 270287, 280547, 283937, 347957, 362237, 364337
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| n, 8*n+1, 64*n+9 and 512*n+73 are primes. [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 04 2010]
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MATHEMATICA
| okQ[n_]:=And@@PrimeQ[NestList[8#+1&, n, 3]]; Select[Prime[Range[50000]], okQ] [From Harvey P. Dale, Jan. 9, 2011]
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PROG
| (MAGMA) [n: n in [1..450000] | IsPrime(n) and IsPrime(8*n+1) and IsPrime(64*n+9) and IsPrime(512*n+73)] [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 04 2010]
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CROSSREFS
| Sequence in context: A170993 A172939 A172234 * A058423 A110027 A179866
Adjacent sequences: A023288 A023289 A023290 * A023292 A023293 A023294
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KEYWORD
| nonn
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AUTHOR
| David W. Wilson (davidwwilson(AT)comcast.net)
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