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Search: id:A099005
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| A099005 |
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Numbers n such that 4*10^n + 6*R_n - 3 is prime, where R_n = 11...1 is the repunit (A002275) of length n. |
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+0
3
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| 1, 2, 3, 4, 6, 7, 8, 12, 23, 59, 75, 144, 204, 268, 760, 1216, 1430, 1506, 1509, 2804, 2924, 3201, 3305, 5753, 9268, 11279, 19677
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Also numbers n such that (14*10^n-11)/3 is a prime number.
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LINKS
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Makoto Kamada, Factorizations of 466...663.
Index entries for primes involving repunits.
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EXAMPLE
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For n = 1, 2, 3, 4, 6, 7, 8 are members since 43, 463, 4663, 46663, 4666663, 46666663
and 466666663 are primes.
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MATHEMATICA
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Do[ If[ PrimeQ[(14*10^n - 11)/3], Print[n]], {n, 0, 10000}] (from Robert G. Wilson v Dec 17 2004)
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CROSSREFS
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Sequence in context: A029748 A018314 A070525 this_sequence A096360 A039087 A093710
Adjacent sequences: A099002 A099003 A099004 this_sequence A099006 A099007 A099008
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KEYWORD
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more,nonn
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AUTHOR
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Julien Peter Benney (jpbenney(AT)ftml.net), Nov 07 2004
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EXTENSIONS
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a(15) - a(21) from Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 22 2004
a(22) - a(25) from Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 17 2005
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
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