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Old 2008-01-16, 10:54   #4
Brian-E's Avatar
Jul 2007
The Netherlands

2·3·5·109 Posts

But isn't the point of the exercise to factorise the Cullen and Woodall numbers and to find the very rare primes, not to discover the alternative representations of the numbers?

Edit: Ah, are you wondering why Prime Pages doesn't list the numbers with the k equal to the n? I think because it lists other numbers of the form k*2^n +/- 1 which are not Cullen/Woodall as well, and the policy is to "simplify" all such numbers so that n is as large as possible. This makes it indeed less simple-looking in the case of the special Cullen/Woodall, but by standardising in that way they make it less likely that someone will make a mistake by analysing a number which has in fact already been tested but written in a different form.

Last fiddled with by Brian-E on 2008-01-16 at 11:04 Reason: Suddenly guessed what you are getting at.
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