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Search: id:A139429
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| A139429 |
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Smallest prime p such that M(n)^2-p*M(n)+1 is prime with M(n)= Mersenne primes =A000668(n). |
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+0
8
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| 3, 19, 3, 3, 73, 7, 271, 1021, 241, 3, 487, 151, 2971, 35839, 5737, 1723, 81943, 115741, 307, 151549, 231823, 443431, 195163, 9973, 114913, 362599
(list; graph; listen)
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OFFSET
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2,1
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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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7*7-3*7+1=29 prime 7=M(2)=2^3-1 so k(2)=3
31*31-19*31+1=373 prime 31=M(3)=2^5-1 so k(3)=19
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CROSSREFS
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Cf. A000668, A139424, A139425, A139426, A139427, A139428, A139430, A139421.
Sequence in context: A157580 A101293 A078096 this_sequence A114365 A084559 A145688
Adjacent sequences: A139426 A139427 A139428 this_sequence A139430 A139431 A139432
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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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