Here’s an interesting characterization of primes: Wilson’s Theorem. A number P is prime if and only if (P-1)! + 1...
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Divisibility by Seven
Everyone learns in grade school some simple tests for divisibility by small numbers such as 2, 3, 5, and 9....
Continue reading...Formula for Primes?
Is there a nice cozy formula that will always spit out primes? Try this one: f(n) = n2 + n +...
Continue reading...Goldbach’s Conjecture
Here’s a famous unsolved problem: is every even number greater than 2 the sum of 2 primes? The Goldbach conjecture, dating from...
Continue reading...Largest Known Primes
Since there are infinitely many primes, what are the largest primes that we know of?The largest known primes are ones of...
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