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Search: id:A101396
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| A101396 |
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Numbers n such that 4*10^n-9 is prime. |
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+0
2
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| 1, 17, 19, 29, 43, 119, 173, 949, 1609, 5579, 19679
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Some of the larger entries may only correspond to probable primes.
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LINKS
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Makoto Kamada, Factorizations of 399...991.
Index entries for primes involving repunits.
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EXAMPLE
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n = 1, 17, 19 are members since 31, 399999999999999991 and 39999999999999999991 are primes.
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MATHEMATICA
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Do[ If[ PrimeQ[4*10^n - 9], Print[n]], {n, 0, 10000}]
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CROSSREFS
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Cf. A095714.
Sequence in context: A132246 A038969 A065742 this_sequence A045803 A098933 A085106
Adjacent sequences: A101393 A101394 A101395 this_sequence A101397 A101398 A101399
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KEYWORD
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hard,nonn
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AUTHOR
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Julien Peter Benney (jpbenney(AT)ftml.net), Jan 15 2005
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EXTENSIONS
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More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
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