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Search: id:A096508
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| A096508 |
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Numbers n for which 8*R_n + 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n. |
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18
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OFFSET
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1,1
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COMMENT
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Also numbers n such that (8*10^n+1)/9 is prime.
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LINKS
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Index entries for primes involving repunits
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EXAMPLE
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n=35 means that 88888888888888888888888888888888889 is a prime number.
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MATHEMATICA
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Do[ If[ PrimeQ[ 8(10^n - 1)/9 + 1], Print[n]], {n, 30000}] (from Robert G. Wilson v Oct 15 2004)
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CROSSREFS
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Cf. A096503, A096504, A096505, A096506, A096507.
Sequence in context: A105453 A121716 A022369 this_sequence A108029 A032476 A059205
Adjacent sequences: A096505 A096506 A096507 this_sequence A096509 A096510 A096511
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KEYWORD
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base,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jul 12 2004
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