Difference between revisions of "Twin prime"

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Two [[prime number | primes]] that differ by exactly 2 are known as '''twin primes'''.  The following are the smallest examples:<br>
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'''Twin primes''' are primes of the form <math>p</math> and <math>p+2</math>.
3, 5<br>
 
5, 7<br>
 
11, 13<br>
 
17, 19<br>
 
29, 31<br>
 
41, 43<br>
 
  
It is not known whether or not there are [[infinite]]ly many pairs of twin primes.  The statement that there are infinitely many pairs of twin primes is known as the [[Twin Prime Conjecture]].
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== Twin Prime Conjecture ==
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{{main|Twin Prime Conjecture}}
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The statement that there are infinitely many pairs of twin primes is known as the [[Twin Prime Conjecture]], which has not been proven yet.
  
One proof that there are infinitely many primes involves showing that the sum of the [[reciprocal]]s of the primes [[diverge]]s.  Thus, a natural strategy to prove that there are infinitely many twin primes is to consider the sum of reciprocals of all the twin primes: <math>B=\frac{1}{3}+\frac{1}{5}+\frac{1}{5}+\frac{1}{7}+\frac{1}{11}+\frac{1}{13}+\frac{1}{17}+\frac{1}{19}+\cdots</math>.
 
Unfortunately, it has been shown that this sum converges to a constant ''B'', known as [[Brun's constant]].  This could mean either that there are [[finite]]ly many twin prime pairs or that they are spaced "too far apart" for that [[series]] to [[diverge]].
 
 
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{{stub}}
 
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[[Category:Definition]]
 
[[Category:Definition]]
 
[[Category:Number Theory]]
 
[[Category:Number Theory]]

Revision as of 20:44, 21 April 2008

Twin primes are primes of the form $p$ and $p+2$.

Twin Prime Conjecture

Main article: Twin Prime Conjecture

The statement that there are infinitely many pairs of twin primes is known as the Twin Prime Conjecture, which has not been proven yet.

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