Fermat number - Wikipedia
en.wikipedia.org › wiki › Fermat_numberFermat numbers and Fermat primes were first studied by Pierre de Fermat, who conjectured that all Fermat numbers are prime. Indeed, the first five Fermat numbers F 0, ..., F 4 are easily shown to be prime. Fermat's conjecture was refuted by Leonhard Euler in 1732 when he showed that
Fermat Numbers - William A. Stein
wstein.org › edu › 20102 Background of Fermat Numbers1 Fermat first conjectured that all the numbers in the form of 2 6 Ù+ 1 are primes. However, in 1732, Leonhard Euler refuted this claim by showing that F5 = 2 32 + 1 = 4,294,967,297 = 641 x 6,700,417 is a composite. It then became a question to whether there are infinitely many
Fermat pseudoprime - Wikipedia
https://en.wikipedia.org/wiki/Fermat_pseudoprime: Def. 3.32 In other words, a composite integer is a Fermat pseudoprime to base a if it successfully passes the Fermat primality test for the base a. The false statement that all numbers that pass the Fermat primality test for base 2, are prime, is called the Chinese hypothesis . The smallest base-2 Fermat pseudoprime is 341.
Fermat numbers - OeisWiki
https://oeis.org/wiki/Fermat_numbers14.01.2020 · The sequence of Fermat numbers is a coprime sequence, since Fn = n − 1 k = 0 Fk+ 2, n≥ 0, where for n= 0 we have the empty product(giving the multiplicative identity, i.e. 1) + 2, giving F0= 3 Since there are infinitely many Fermat numbers, all mutually coprime, this implies that there are infinitely many prime numbers. Generating function
Fermat number - Wikipedia
https://en.wikipedia.org/wiki/Fermat_numberIn mathematics, a Fermat number, named after Pierre de Fermat, who first studied them, is a positive integer of the form where n is a non-negative integer. The first few Fermat numbers are: 3, 5, 17, 257, 65537, 4294967297, 18446744073709551617, ... (sequence A000215 in the OEIS).If 2 + 1 is primeand k > 0, then k must be a power of 2, so 2 + 1 is a Fermat number; such primes …
The Prime Glossary: Fermat number
primes.utm.edu › glossary › xpageThis is usually taken to be the conjecture that every number of the form is prime. So we call these the Fermat numbers, and when a number of this form is prime, we call it a Fermat prime. The only known Fermat primes are the first five Fermat numbers: F 0 =3, F 1 =5, F 2 =17, F 3 =257, and F 4 =65537.
Fermat numbers - PlanetMath
www.planetmath.org › FermatNumbersalthough he had no proof. The first 5 Fermat numbers: 3,5,17,257,65537(corresponding to n=0,1,2,3,4) are all primes (so called Fermat primes) (In fact, F5=641×6700417). Moreover, no other Fermat number is known to be prime for n>4, so now it is conjectured that those are all prime Fermat numbers.