Wilson's theorem - Wikipedia
en.wikipedia.org › wiki › Wilson&In number theory, Wilson's theorem states that a natural number n > 1 is a prime number if and only if the product of all the positive integers less than n is one less than a multiple of n. That is (using the notations of modular arithmetic ), the factorial ( n − 1 ) ! = 1 × 2 × 3 × ⋯ × ( n − 1 ) {\displaystyle (n-1)!=1\times 2\times 3\times \cdots \times (n-1)} satisfies
A proof of Wilson's Theorem - PrimePages
primes.utm.edu › notes › proofsA proof of Wilson's Theorem. In 1770 Edward Waring announced the following theorem by his former student John Wilson. Wilson's Theorem. Let p be an integer greater than one. p is prime if and only if (p-1)! ≡ -1 (mod p). This beautiful result is of mostly theoretical value because it is relatively difficult to calculate (p-1)!
Wilson's Theorem - GeeksforGeeks
www.geeksforgeeks.org › wilsons-theoremDec 15, 2015 · Wilson’s Theorem. Difficulty Level : Easy. Last Updated : 19 Nov, 2016. Wilson’s theorem states that a natural number p > 1 is a prime number if and only if. (p - 1) ! ≡ -1 mod p OR (p - 1) ! ≡ (p-1) mod p. Examples: p = 5 (p-1)! = 24 24 % 5 = 4 p = 7 (p-1)! = 6! = 720 720 % 7 = 6.
Wilson's theorem - Wikipedia
https://en.wikipedia.org/wiki/Wilson's_theoremThe proofs (for prime moduli) below use the fact that residue classes modulo a prime number are fields - see the article prime field for more details. Lagrange's theorem, which states that in any field a polynomial of degree n has at most n roots, is needed for all the proofs. If n is composite it is divisible by some prime number q, where 2 ≤ q ≤ n − 2. Because divides , let for some integer . Suppose for the sake of contradiction that (n − 1)! were congruent to −1 (mod …