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Search: id:A139427
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| A139427 |
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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, 3, 5, 17, 17, 5, 83, 63, 71, 101, 543, 59, 569, 1029, 353, 1851, 2801, 2619, 525, 2907, 8955, 437, 30159, 5409, 8355
(list; graph; listen)
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OFFSET
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1,2
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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=13 prime 3=M(1)=2^2-1 so k(1)=1
7*7+3*7+1=71 prime 7=M(2)=2^3-1 so k(2)=3
31*31+5*31+1=1117 prime 31=M(3)=2^5-1 so k(3)=5
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CROSSREFS
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Cf. A000668, A139424, A139425, A139426, A139428, A139429, A139430, A139421.
Adjacent sequences: A139424 A139425 A139426 this_sequence A139428 A139429 A139430
Sequence in context: A038120 A105408 A085418 this_sequence A035089 A040129 A045415
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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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