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A127997 Numbers n such that (22^n - 1)/21 is prime. +0
13
2, 5, 79, 101, 359, 857, 4463, 9029, 27823 (list; graph; listen)
OFFSET

1,1

COMMENT

9029 is a term found by Richard Fischer in 2004. - Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 11 2007

REFERENCES

H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.

LINKS

H. Lifchitz, Mersenne and Fermat primes field

MATHEMATICA

Select[Prime[Range[100]], PrimeQ[(22^#-1)/21]&]

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 this_sequence A096266 A123978 A120798

Adjacent sequences: A127994 A127995 A127996 this_sequence A127998 A127999 A128000

KEYWORD

hard,more,nonn

AUTHOR

Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 11 2007

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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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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