Prime number: Difference between revisions
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=== Twin Primes === | === Twin Primes === | ||
Two primes that differ by exactly 2 are known as [[twin primes]]. The following are the smallest examples: | Two primes that differ by exactly 2 are known as [[twin primes]]. The following are the smallest examples:<br> | ||
3, 5 | 3, 5<br> | ||
5, 7 | 5, 7<br> | ||
11, 13 | 11, 13<br> | ||
17, 19 | 17, 19<br> | ||
29, 31 | 29, 31<br> | ||
41, 43 | 41, 43<br> | ||
Revision as of 23:35, 19 June 2006
A prime number (or simply prime) is a positive integer
whose only positive divisors are 1 and itself.
Note that
is usually defined as being neither prime nor composite because it is its only factor among the natural numbers.
Famous Primes
Fermat Primes
Mersenne Primes
Twin Primes
Two primes that differ by exactly 2 are known as twin primes. The following are the smallest examples:
3, 5
5, 7
11, 13
17, 19
29, 31
41, 43
Advanced Definition
When the need arises to include negative divisors, a prime is defined as an integer p whose only divisors are 1, -1, p, and -p.