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Search: id:A128472
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| A128472 |
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a(n) = smallest prime of the form (2n-1)^k - 2 for k>(2n-1), or 0 if no such number exists. |
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13
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OFFSET
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1,2
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COMMENT
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a(6) = 11^22420 - 2 was found by Rick L. Shepherd 09/29/2007. It has 23349 decimal digits and it is too large to include.
a(7)-a(12) = {771936328432730777189183517369830159827426282764863750131729657829597399846468418688727, 98526125335693359373, 339448671314611904643504117119, 37589973457545958193355599, 1136272165922724266740722458520499, 480250763996501976790165756943039}.
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LINKS
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Henri Lifchitz & Renaud Lifchitz : PRP Records. Probable Primes Top 10000.
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CROSSREFS
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Cf. A084714 = smallest prime of the form (2n-1)^k - 2, or 0 if no such number exists.
Cf. A133856 = least number k>(2n-1) such that (2n-1)^k - 2 is prime, or 0 if no such number exists.
Cf. A014224, A109080, A090669, A128455, A128457, A128458, A128459, A128460, A128461. Cf. A133858, A133982.
Sequence in context: A138917 A116327 A060711 this_sequence A093404 A031136 A050456
Adjacent sequences: A128469 A128470 A128471 this_sequence A128473 A128474 A128475
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KEYWORD
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nonn
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AUTHOR
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Alexander Adamchuk (alex(AT)kolmogorov.com), Mar 14 2007, Oct 01 2007
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EXTENSIONS
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Edited by Max Alekseyev (maxale(AT)gmail.com), Sep 18 2009
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