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Search: id:A139424
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| A139424 |
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Smallest number k such that M(n)^2-k*M(n)-1 is prime with M(n)= Mersenne primes =A000668(n). |
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+0
8
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| 1, 1, 1, 1, 1, 43, 1, 41, 53, 91, 317, 317, 43, 1, 37, 3595, 563, 17239, 911, 11497, 58501, 1259, 10283, 138569, 72247, 27733
(list; graph; listen)
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OFFSET
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1,6
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COMMENT
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All primes certified using openpfgw_v12 from primeform group
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EXAMPLE
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3*3-1*3-1=5 prime 3=M(1)=2^2-1 so k(1)=1
7*7-1*7-1=41 prime 7=M(2)=2^3-1 so k(2)=1
31*31-1*31-1=929 prime 31=M(3)=2^5-1 so k(3)=1
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CROSSREFS
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Cf. A000668, A139425, A139426, A139427, A139428, A139429, A139430, A139421.
Sequence in context: A152508 A070177 A114786 this_sequence A051318 A036202 A107814
Adjacent sequences: A139421 A139422 A139423 this_sequence A139425 A139426 A139427
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KEYWORD
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hard,more,nonn
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AUTHOR
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Pierre CAMI (pierrecami(AT)tele2.fr), Apr 21 2008
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