Probable Prime
In number theory, a probable prime (PRP) is an integer that satisfies a specific condition also satisfied by all prime numbers. Different types of probable primes have different specific conditions. While there may be probable primes that are composite (called pseudoprimes), the condition is generally chosen in order to make such exceptions rare.
Fermat's test for compositeness, which is based on Fermat's little theorem, works as follows: given an integer n, choose some integer a coprime to n and calculate an − 1 modulo n. If the result is different from 1, n is composite. If it is 1, n may or may not be prime; n is then called a (weak) probable prime to base a.
Read more about Probable Prime: Properties, Variations
Famous quotes containing the words probable and/or prime:
“... it is probable that in a fit of generosity the men of the United States would have enfranchised its women en masse; and the government now staggering under the ballots of ignorant, irresponsible men, must have gone down under the additional burden of the votes which would have been thrown upon it, by millions of ignorant, irresponsible women.”
—Jane Grey Swisshelm (1815–1884)
“Sometimes it takes years to really grasp what has happened to your life. What do you do after you are world-famous and nineteen or twenty and you have sat with prime ministers, kings and queens, the Pope? What do you do after that? Do you go back home and take a job? What do you do to keep your sanity? You come back to the real world.”
—Wilma Rudolph (1940–1994)