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Joined: Dec 2000
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Carpal Tunnel
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Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
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Joined: Mar 2000
Posts: 315
enthusiast
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enthusiast
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the previous ones are the Fermat primes, indeed of this kind(2^(2^n))+1
The problem is that , given n, it is not known usually if the corresponding Fermat number is prime (usually not)
The Mersenne primes are
2^n - 1 ( I was not aware that this way of writing was almost universally understood) - when they are prime themselves.
n has to be prime indeed (Faldage, you were right) because if n = ab, then the above number cannot be prime
In that case, you could write
(2^a)^b - 1^b =
[2^a - 1 ] times { something else}
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Joined: Dec 2000
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Carpal Tunnel
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Carpal Tunnel
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almost universally understood
The ^ is a common operator for exponentiation in computer languages such as BASIC.
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Joined: Mar 2000
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I know, of course, but I didn't assume that this knowledge is spread around...
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Carpal Tunnel
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Carpal Tunnel
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If it's any consolation, Emanuela, I certainly didn't know!
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Joined: Dec 2000
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Carpal Tunnel
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Carpal Tunnel
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spread around
Perhaps "scattered around" would be a better phrase. That is, it's widely known but not by that many people.
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