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Search: id:A086661
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| A086661 |
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Numbers n such that n*4^n-1 is prime. |
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+0
1
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| 3, 5, 8, 14, 23, 63, 107, 132, 428, 530, 1137, 1973, 2000, 7064, 20747, 79574, 113570
(list; graph; listen)
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OFFSET
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1,1
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REFERENCES
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H. Dubner, Generalized Cullen Numbers, J. Rec. Math, 21 (No. 3, 1989).
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LINKS
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Steven Harvey, Generalized Woodall Search
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EXAMPLE
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3 is in the sequence because 3*4^3-1=191 is prime.
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MATHEMATICA
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Do[If[PrimeQ[n*4^n-1], Print[n]], {n, 4000}]
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CROSSREFS
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Cf. A007646, A002234, A005849.
Adjacent sequences: A086658 A086659 A086660 this_sequence A086662 A086663 A086664
Sequence in context: A094007 A109022 A023596 this_sequence A078065 A072655 A108301
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KEYWORD
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nonn
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AUTHOR
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Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Jul 27 2003
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EXTENSIONS
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One more term from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Nov 23 2004
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
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