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A127997
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Numbers n such that (22^n - 1)/21 is prime.
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13
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OFFSET
| 1,1
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COMMENTS
| 9029 is a term found by Richard Fischer in 2004. - Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 11 2007
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REFERENCES
| H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.
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LINKS
| H. Lifchitz, Mersenne and Fermat primes field
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MATHEMATICA
| Select[Prime[Range[100]], PrimeQ[(22^#-1)/21]&]
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CROSSREFS
| Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035. Cf. A127995, A127996, A127998, A127999, A128000, A098438, A128002, A128003, A128004, A128005.
Sequence in context: A102983 A038583 A082080 * A096266 A123978 A201113
Adjacent sequences: A127994 A127995 A127996 * A127998 A127999 A128000
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KEYWORD
| hard,more,nonn
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AUTHOR
| Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 11 2007
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EXTENSIONS
| More terms from Ryan Propper (rpropper(AT)stanford.edu), Mar 29 2007
27823 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
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