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A007011 a(n) = smallest pseudoprime to base 2 with n prime factors.
(Formerly M5444)
4
341, 561, 11305, 825265, 45593065, 370851481, 38504389105, 7550611589521, 277960972890601, 32918038719446881, 1730865304568301265, 606395069520916762801, 59989606772480422038001, 6149883077429715389052001, 540513705778955131306570201, 35237869211718889547310642241 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Smallest composite number m with n prime factors such that 2^(m-1)-1 is divisible by m.

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=2..17.

R. Pinch, Pseudoprimes up to 10^13, Proceedings ANTS-IV, 4th Algorithmic Number Theory Symposium, Leiden, 2000. Springer Lecture Notes in Computer Science 1838 (2000) 459--474.

Index entries for sequences related to pseudoprimes

CROSSREFS

Cf. A007535.

Sequence in context: A210993 A006970 A007324 * A064907 A043685 A043576

Adjacent sequences:  A007008 A007009 A007010 * A007012 A007013 A007014

KEYWORD

nonn,nice

AUTHOR

Richard Pinch

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007

STATUS

approved

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Last modified October 18 12:18 EDT 2019. Contains 328160 sequences. (Running on oeis4.)