Twin Prime

A twin prime is a prime number that differs from another prime number by two, for example the twin prime pair (41, 43). Sometimes the term twin prime is used for a pair of twin primes; an alternative name for this is prime twin or prime pair.

List of unsolved problems in mathematics
Are there infinitely many twin primes?

Read more about Twin Prime:  History, Brun's Theorem, Largest Known Twin Prime Pair, Properties, First Hardy–Littlewood Conjecture, Polignac's Conjecture, Isolated Prime

Famous quotes containing the words twin and/or prime:

    That Dali is really Norman Rockwell’s twin brother kidnapped by gypsies in babyhood.
    Vladimir Nabokov (1899–1977)

    Faith in reason as a prime motor is no longer the criterion of the sound mind, any more than faith in the Bible is the criterion of righteous intention.
    George Bernard Shaw (1856–1950)