Carmichael number: Difference between revisions

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==Definition==
==Definition==


A composite number <math>n > 1</math> is termed an '''absolute pseudoprime''' or ''Carmichael number''' if it satisfies the following condition:
A composite number <math>n > 1</math> is termed an '''Carmichael number''' or '''absolute pseudoprime''' if it satisfies the following condition:


* The [[defining ingredient::Liouville-lambda function]] of <math>n</math> divides <math>n - 1</math>.
* The [[defining ingredient::Liouville-lambda function]] of <math>n</math> divides <math>n - 1</math>.
* For any natural number <math>a</math> relatively prime to <math>n</math>, <math>n</math> divides <math>a^{n-1} - 1</math>.
* For any natural number <math>a</math> relatively prime to <math>n</math>, <math>n</math> divides <math>a^{n-1} - 1</math>.
* <math>n</math> is a [[defining ingredient::Fermat pseudoprime]] to any base relatively prime to it.
* <math>n</math> is a [[defining ingredient::Fermat pseudoprime]] to any base relatively prime to it.
==Facts==
* [[There are infinitely many Carmichael numbers]]

Revision as of 22:38, 6 April 2009

Template:Pseudoprimality property

Definition

A composite number is termed an Carmichael number or absolute pseudoprime if it satisfies the following condition:

  • The Liouville-lambda function of divides .
  • For any natural number relatively prime to , divides .
  • is a Fermat pseudoprime to any base relatively prime to it.

Facts