Talk:Cullen number

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Mathematics rating:	Stub Class	Low Priority	Field: Number theory
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. Geometry guy 22:11, 22 May 2007 (UTC)

[edit] weak property

It migt be true, that a Cullen number C_p is divisible by 2p-1, if p is a prime and p = 8k − 3. But there exist other C_p is divisible by 2p-1, where p is not equal to 8k-3. At last there exist n there neither prime nor of the form 8k-1, but C_n is divisble by 2n-1.

 n   c(n)  2n-1  8k-3   d/n
----------------------------
 1      3     1           d
 2      9     3           d
 3     25     5     1     d
 4     65     7           n
 5    161     9           n
 6    385    11           d
 7    897    13     2     d
 8   2049    15           n
 9   4609    17           n
10  10241    19           d
11  22529    21           n
12  49153    23           d

I think, this is a very weak property. --Arbol01 18:07, 11 Feb 2005 (UTC)