PrimeCount

26 July

Prime the first 1,000,000 numbers

Here i have list of prime number million number, starting from 2 and ending at 15,485,863.

Click the link to download the zip file.

  Prime 1st 1,000,000 (2.3 MiB, 94 hits)

25 July

Mersenne prime

In mathematics, a Mersenne number is a number that is one less than a power of two,

Mn = 2n − 1.

A Mersenne prime is a Mersenne number that is a prime number. As of August 2007, only 44 Mersenne primes are known; the largest known prime number (232,582,657−1) is a Mersenne prime and in modern times the largest known prime has nearly always been a Mersenne prime. Like several previous Mersenne primes, it was discovered by a distributed computing project on the Internet, known as the Great Internet Mersenne Prime Search (GIMPS).

About Mersenne primes

Many fundamental questions about Mersenne primes remain unresolved. It is not even known whether there is a largest Mersenne prime, which would mean that the set of Mersenne primes is finite. The Lenstra-Pomerance-Wagstaff conjecture asserts that, on the contrary, there are infinitely many Mersenne primes and predicts their order of growth. It is also not known whether infinitely many Mersenne numbers with prime exponents are composite, although this would follow from widely believed conjectures about prime numbers, for example, the infinitude of Sophie Germain primes.

A basic theorem about Mersenne numbers states that in order for Mn to be a Mersenne prime, the exponent n itself must be a prime number. This rules out primality for numbers such as M4 = 24−1 = 15: since the exponent 4=2×2 is composite, the theorem predicts that 15 is also composite; indeed, 15 = 3×5. The three smallest Mersenne primes are

M2 = 3, M3 = 7, M5 = 31.

While it is true that only Mersenne numbers Mp, where p = 2, 3, 5, … could be prime, it may nevertheless turn out that Mp is not prime even for a prime exponent p. The smallest counterexample is the Mersenne number

M11 = 211 − 1 = 2047 = 23 × 89,

which is not a Mersenne prime, even though 11 is a prime number. The lack of an obvious rule to determine whether a given Mersenne number is prime makes the search for Mersenne primes an interesting task, which becomes difficult very soon, since Mersenne numbers grow very fast. The Lucas–Lehmer test for Mersenne numbers is an efficient primality test that greatly aids this task. Search for the largest known prime has somewhat of a cult following. Consequently, a lot of computer power has been expended searching for new Mersenne primes, much of which is now done using distributed computing.

Mersenne primes are used in pseudorandom number generators such as Mersenne Twister and Park–Miller RNG.

Searching for Mersenne primes

The identity

2^{ab}-1=(2^a-1)\cdot \left(1+2^a+2^{2a}+2^{3a}+\dots+2^{(b-1)a}\right)

shows that Mn can be prime only if n itself is prime—that is the primeness of n is necessary but not sufficient for Mn to be prime—which simplifies the search for Mersenne primes considerably. (This follows very simply from the Mersenne property of the sequence of numbers of the form xnyn. This states that xaya | xbyb if and only if a|b.) The converse statement, namely that Mn is necessarily prime if n is prime, is false. The smallest counterexample is 211−1 = 23×89, a composite number.

Fast algorithms for finding Mersenne primes are available, and the largest known prime numbers as of 2007 are Mersenne primes.

The first four Mersenne primes M2 = 3, M3 = 7, M5 = 31 and M7 = 127 were known in antiquity. The fifth, M13 = 8191, was discovered anonymously before 1461; the next two (M17 and M19) were found by Cataldi in 1588. After nearly two centuries, M31 was verified to be prime by Euler in 1772. The next (in historical, not numerical order) was M127, found by Lucas in 1876, then M61 by Pervushin in 1883. Two more (M89 and M107) were found early in the 20th century, by Powers in 1911 and 1914, respectively.

The best method presently known for testing the primality of Mersenne numbers is based on the computation of a recurring sequence, as developed originally by Lucas in 1856 and improved by Lehmer in the 1930s, now known as the Lucas-Lehmer test for Mersenne numbers. Specifically, it can be shown that (for n > 2) Mn = 2n − 1 is prime if and only if Mn divides Sn−2, where S0 = 4 and for k > 0, S_k=S_{k-1}^2-2.

Mersenne prime found graph

 

The search for Mersenne primes was revolutionized by the introduction of the electronic digital computer. The first successful identification of a Mersenne prime, M521, by this means was achieved at 10:00 P.M. on January 30, 1952 using the U.S. National Bureau of Standards Western Automatic Computer (SWAC) at the Institute for Numerical Analysis at the University of California, Los Angeles, under the direction of Lehmer, with a computer search program written and run by Prof. R.M. Robinson. It was the first Mersenne prime to be identified in thirty-eight years; the next one, M607, was found by the computer a little less than two hours later. Three more — M1279, M2203, M2281 — were found by the same program in the next several months. M4253 is the first Mersenne prime that is titanic, M44497 is the first gigantic, and M6,972,593 was the first megaprime to be discovered, being a prime with at least 1,000,000 digits. All three were the first known prime of any kind of that size.

Reference: http://wikipedia.org

25 July

Prizes for finding the largest prime

 

The Electronic Frontier Foundation (EFF) is giving out awards to whom ever find the largest prime number know to humankind, the award is call “EFF Cooperative Computing Awards”. Prizes consist of the following;

  • $50,000 to the first individual or group who discovers a prime number with at least 1,000,000 decimal digits (awarded Apr. 6, 2000)
  • $100,000 to the first individual or group who discovers a prime number with at least 10,000,000 decimal digits
  • $150,000 to the first individual or group who discovers a prime number with at least 100,000,000 decimal digits
  • $250,000 to the first individual or group who discovers a prime number with at least 1,000,000,000 decimal digits

This look like a promising award for me to advance my research into more advance mathematics, Interestingly that if I program a software that run as screen saver and help me process the prime numbers. I’ll keep everyone posted on this topic.

24 July

Prime Found Widget

I alway like the real time environment of things. and here i have my little widget that get update everytime my home server that is processing the prime numbers, i have re-develop the software to work as a Windows Service. My electricity tend to black out from time to time, therefore i need a software that can automate start up again after the server restart with the power come back online. Also due that my server is Windows Server 2003, you can not logon without a password if you would like the server to be access via the internet. Well here it is, my little progress widget;

22 July

Progress of finding prime numbers

Hi! Everyone, Can anyone guest how fast can 2 x Dual-core Xeon 2.4GHz with HT search for prime numbers with only 9 digit points (below 100,000,000)?

My prime server runing at 2008-7-22

Image 1 Server progress screen shot

Not fast at all, I run the server for 2 two now with average CPU utilization of 91%. First I imagine my notebook was slow, I programmed the search program to fully profit from concurrency threading technology of modern processers. Here a screen of the server processing graph;

I’m thinking of trying out Windows HPC Server 2008, to help speed up things. But a little low on budget here, if anyone could help in the research would be a great thank you from me.

20 July

Prime below 1,000

Here we have a list of prime numbers that are below 1,000. click to download.

  Prime1st-2thusand (4.6 KiB, 72 hits)

20 July

Welcome to PrimeCount.com

PrimeCount! Hunt for the largest prime number known to humankind, founded by Sarin Na Wangkanai and friends. In order to collaborate everyone from IT experts, scientists, mathematicians, hobbyists, and interested individuals. Providing a center of database to pull from when needed, to update on current progress of known found largest prime numbers.

We hope that this website is useful to humankind, dedicated for research in the area of advance mathematics. If whom is interested to join and/or collaborate in the project please contact us at center(a)primecount.com