Talk:Carmichael number

From Citizendium
Revision as of 17:50, 8 November 2008 by imported>Karsten Meyer (→‎Carmichael numbers / Euler pseudoprimes)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
Code [?]
 
To learn how to update the categories for this article, see here. To update categories, edit the metadata template.
 Definition A composite number c such that ac−1 ≡ 1 (mod c) for all a that are coprime with c. [d] [e]
Checklist and Archives
 Workgroup category Mathematics [Categories OK]
 Talk Archive none  English language variant American English

Carmichael numbers / Euler pseudoprimes

I'm not sure why it's asserted that every CN is an Euler pseudoprime. 2821 is a counterexample base 2, since 2^2821 == 1520 mod 2821, but 2821=7.13.31, lambda(2821) = lcm{6,12.30} = 60 and 60 | 2820. Richard Pinch 19:01, 22 October 2008 (UTC)

2821 is to many Bases eulerpseudoprime. It is eulerpseudoprime to the Bases: 3, 4, 9, 10, 12, 16, 17, 22, 23, 25, 27, 29, 30, ...
So 2821 is a Carmichael number, and it is an euler pseudoprime too. Not to every base, but to many bases. --Karsten Meyer 23:50, 8 November 2008 (UTC)