9 Years
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Last Post by ithelp

Wow, that's a big prime :)

It took my computer a few minutes to generate a 13/14 diget prime with a program I made, i'm curious how they discovered such a massive one.


He was a member of the GIMPS network - he signed up and was issued a2^P-1 number and his computer worked on it on its down-time for a month or so. Actually, pretty boring - I prefer to use BOINC to keep my computers occupied in their spare time.


there is a psudo one to one function for the prime numbers
but it will fail on above that limit.

I got hard time when reading those things mathematical mumbo
jumbo. However I'm reading it again grimjack.May be later I can underestood that function.

Prime numbers are really Industrial the fieds like Applied Cryptography and cryptanalysis. so worth to learn the math
behind them.

source : wiki page for prime numbers.


There are some mathematical tricks for shortening the search; I do not know them all but the first would be to divide the number by all the known primes.

do mod[TEX] n/P[/TEX] until mod[TEX]n/P = 0[/TEX]or [TEX]P>n/3[/TEX]

Where P is a list of all known primes and I am too lazy to look up the code for reading incrementally from a list.

The formula 2^P-1 eliminates any number divisible by 2.

I am not a programmer so the code is probably wrong but the essential trick is that all factors of a number will eventually be prime numbers, no factor greater than n/3 will be cardinal. I am not actually a mathematician either so I am working from a logic standpoint so please let me know if/where I go wrong.


I seem to have moved more to the left since I last took this test - must be the joy of having someone on my side in the government

This will come as no surprise to anyone here:
You are a far-left moderate social libertarian.
Left: 8.01, Libertarian: 2.3

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Few years back someone from IIT, Kanpur , India has invented a polynomial time algorithm to detect whether a number is prime or not , so I guess prime is no longer that challenging problem.

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