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Search: id:A130640
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| A130640 |
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Numbers n such that either 2^n+p(n) or 2^n-p(n) is prime, where p(n) denotes the n-th prime. |
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+0
1
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| 2, 3, 4, 5, 11, 12, 13, 14, 19, 23, 24, 26, 57, 61, 96, 106, 175, 189, 226, 227, 311, 312, 373, 483, 741, 1046, 1298, 1787, 1952, 2130, 2285, 2670, 3254, 3642, 4369, 4741, 7082, 8421, 10695, 13559, 14802, 18824, 18892, 20655
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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2^5 + p(5) = 32 + 11 = 43; 43 is prime, hence 5 is in the sequence.
2^11 - p(11) = 2048 - 31 = 2017; 2017 is prime, therefore 11 is in the sequence.
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MATHEMATICA
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Select[Range[2000], PrimeQ[2^# - Prime[ # ]] || PrimeQ[2^# + Prime[ # ]] &]
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CROSSREFS
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Cf. A078583, A077375.
Sequence in context: A115306 A084545 A069908 this_sequence A116068 A104420 A052418
Adjacent sequences: A130637 A130638 A130639 this_sequence A130641 A130642 A130643
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KEYWORD
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nonn
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AUTHOR
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J. M. Bergot (thekingfishb(AT)yahoo.ca), Jun 19 2007
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EXTENSIONS
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Edited and extended by Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jun 24 2007
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