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A108573 Least positive k such that k * [RSA-640]^n - 1 is prime, where RSA-640 is the 193 decimal digit RSA challenge number. 4
390, 1334, 136, 2058, 2710, 2082, 748, 2388, 3588, 1902, 988, 9170, 5076, 28778, 2112, 1800, 3082, 1238, 12916 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Other terms are a(25)=1558 and a(43)=5718. All values in the sequence are Fermat and Lucas PRPs except for the first two which were proved with ECM. The larger values won't be easily provable until RSA-640 is factored, which has a prize of $20,000 for its factorization. This sequence is based on a suggestion of Jens Kruse Andersen.
RSA-640 was factored in 2005; see the Wikipedia link. - D. S. McNeil, Nov 26 2010
LINKS
Wikipedia, RSA-640
CROSSREFS
Cf. A108375.
Sequence in context: A136153 A069477 A325993 * A206653 A202429 A236612
KEYWORD
more,nonn
AUTHOR
Jason Earls, Jul 05 2005
EXTENSIONS
Edited and a(19) added by D. S. McNeil, Nov 25 2010
STATUS
approved

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Last modified April 19 23:15 EDT 2024. Contains 371798 sequences. (Running on oeis4.)