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[QUOTE=David John Hill Jr;182267]I had been meaning to post this elsewhere , but this looks like a better place.
Of very rare occurence and usage. Begin at (p-1)!+1= K*p (AS befitting Wilson's theorem.) Perform K+1, then as given 2^p-1 and a corresponding 2^(p-1), then 2^(p-1) | K+1 In reverse , as an integer multiple of 2^(p-1) subtract 1, and one has K, the Wilson's theorem proof coefficient. Two cases where this appears to hold(and possibly on up by induction) is 2^3-1 and 2^7-1.(and should therefor really be included in the given statement) As 'academic' to the whole picture that this may appear, they are(exist) cases where going the perfect way should be a lot faster than full scale wilson calculation.[/QUOTE] Doesn't this still require knowing the value of p? |
Additionally, if we consider
[tex](2^p -1)(2^{p-1})=\sum_{i=0}^{p-1} {2^i} + \sum_{j=0}^{p-2} {2^j(2^p-1)}[/tex] then the number of distinct factors for the associated perfect number of any Mersenne prime can be given by: factors = 1 + (p-1) + 1 + (p-2) + 1 = (2p-3) + 3 = [B]2*p[/B] factors Just something interesting I just noticed. |
[QUOTE=Primeinator;182298]Additionally, if we consider
[tex](2^p -1)(2^{p-1})=\sum_{i=0}^{p-1} {2^i} + \sum_{j=0}^{p-2} {2^j(2^p-1)}[/tex] then the number of distinct factors for the associated perfect number of any Mersenne prime can be given by: factors = 1 + (p-1) + 1 + (p-2) + 1 = (2p-3) + 3 = [B]2*p[/B] factors Just something interesting I just noticed.[/QUOTE] That's pretty easy to see directly. Assuming 2^{p}-1 is prime, all of your factors are either one of $p$ powers of 2 (2^0,2^1,/ldots, 2^{p-1}), or one of $p$ powers of two times the associated Mersenne prime ((2^0*(2^{p}-1),2^1*(2^{p}-1),/ldots, 2^{p-1}*(2^{p}-1)), for $2p$ distinct factors. /too drunk to bother with the tex tags |
In response to 2nd to last entry
To clarify, I was not suggesting a shortcut for a search for a p in general. The examples are just that , as occuring.For examples much higher the numbers are too great to verify with my software, and so , to verify a pattern
of the division by some 2^(p-1), as going this way. I was simply noting the occurence of the +1 to the K of Wilson and division by the 2^(p-1) as being another whole number, and further as far as computing it might be a faster way around. As to the original thread post, back to the last entry-------- |
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