Tag Archives: prime

Mersenne primes and the Lucas-Lehmer test

Posted on January 17, 2013 by

Mersenne numbers, named after Marin Mersenne, are numbers of the form . The first few Mersenne numbers are therefore , , , , , and so on. Mersenne numbers come up all the time in computer science (for example, is … Continue reading →

Posted in arithmetic, computation, famous numbers, iteration, modular arithmetic, number theory, primes | Tagged , , , , | 3 Comments

Fun with repunit divisors: proofs

Posted on November 16, 2011 by

As promised, here are some solutions to the repunit puzzle posed in my previous post. (Stop reading now if you don’t want to see solutions yet!) Prove that every prime other than 2 or 5 is a divisor of some … Continue reading →

Posted in iteration, modular arithmetic, number theory, pattern, primes, proof | Tagged , , , , | 1 Comment

Book Review: The Mystery of the Prime Numbers

Posted on November 7, 2010 by

Several months ago, Matthew Watkins sent me a review copy of his new book, Secrets of Creation Volume One: The Mystery of the Prime Numbers. It’s taken me a while to get around to reviewing it, but not for lack … Continue reading →

Posted in books, number theory, primes, review | Tagged , , , | 3 Comments

Two Very Large primes

Posted on September 17, 2008 by

As promised, I can now reveal the identity of the two newly discovered Mersenne primes. The smaller of the two, discovered on September 6 by Hans-Michael Elvenich in Langenfeld, Germany, is an 11,185,272-digit number which you can download here. The … Continue reading →

Posted in computation, famous numbers, links, primes | Tagged , , , | 3 Comments

New Mersenne primes!

Posted on September 15, 2008 by

The Great Internet Mersenne Prime Search just announced not one, but two new Mersenne primes! You might also recall the last time they announced a new prime, in September 2006, so these new primes were found almost exactly two years … Continue reading →

Posted in computation, famous numbers, links, primes | Tagged , , , , | 1 Comment