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A059242
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Numbers n such that 2^n + 5 is prime.
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8
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1, 3, 5, 11, 47, 53, 141, 143, 191, 273, 341, 16541, 34001, 34763, 42167
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| 2^p+5 is prime for p=(3, 5, 11, 47, 53, 191) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 07 2010]
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EXAMPLE
| 2^3 + 5 = 13 is prime but 2^4 + 5 = 21 is not.
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MATHEMATICA
| Select[Range[20000], PrimeQ[2^#+5]&] (*From Vladimir Joseph Stephan Orlovsky, Feb 26 2011*)
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CROSSREFS
| Sequence in context: A105236 A144467 A049883 * A175173 A004203 A201473
Adjacent sequences: A059239 A059240 A059241 * A059243 A059244 A059245
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KEYWORD
| nonn,hard
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AUTHOR
| Tony Davie (ad(AT)dcs.st-and.ac.uk), Jan 21 2001
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EXTENSIONS
| More terms from Santi Spadaro, Oct 04, 2002
a(12) from Hans Havermann, Oct 07 2002
a(13)-a(15) from Charles R Greathouse IV, Oct 07 2011
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