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)
“What was lost in the European cataclysm was not only the Jewish past—the whole life of a civilization—but also a major share of the Jewish future.... [ellipsis in source] It was not only the intellect of a people in its prime that was excised, but the treasure of a people in its potential.”
—Cynthia Ozick (b. 1928)