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42nd Mersenne Prime Confirmed
Jazzer_Techie writes "The possible Mersenne Prime discovered last week has now been confirmed. This prime has 7,816,230 digits, which makes it not only the largest Mersenne Prime, but also the largest prime of any kind ever discovered. For those who don't want to take time to read the article, the prime is 2^25,964,951 - 1."
There actually are very good algorithms for finding primality. It has reached the point where proving a number prime is MUCH easier than finding any factors of it.
There are two types. One is deterministic, and will give you absolute proof that the tested number is prime. The other type is probability based. These are more popular. The most widely used is known as the Miller-Rabin test. It is known to be absolutely correct for all n 3*10^16. For larger n, it will never report a composite to be prime, but there is a small (around 10^-20) chance the "prime" number will be composite. There are no known prime numbers that Miller-Rabin reports to be composite.
In the case of Mersenne numbers, it's a different story. There is a deterministic algorithm called the Lucas-Lehmer test. This will determine whether 2^p-1 is prime with O-notation p! The catch of course is that it only works for Mersenne numbers.
E = m c^3 Don't drink and derive E = m c^3
that the digits make a phone number?? 225-964-9511 used to dial the residence of a man in Baton Rouge, Louisiana.
Now all you get is "the number you have dialed is not a working number"
Could this be the first telephone slashdotting in history!?
Wikileaks, no DNS