enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. List of prime numbers - Wikipedia

    en.wikipedia.org/wiki/List_of_prime_numbers

    This is a list of articles about prime numbers. A prime number (or prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. By Euclid's theorem, there are an infinite number of prime numbers. Subsets of the prime numbers may be generated with various formulas for primes.

  3. Ulam spiral - Wikipedia

    en.wikipedia.org/wiki/Ulam_spiral

    The number 1 has only a single factor, itself; each prime number has two factors, itself and 1; composite numbers are divisible by at least three different factors. Using the size of the dot representing an integer to indicate the number of factors and coloring prime numbers red and composite numbers blue produces the figure shown.

  4. Prime number - Wikipedia

    en.wikipedia.org/wiki/Prime_number

    A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 4 is composite because it is a ...

  5. Landau's problems - Wikipedia

    en.wikipedia.org/wiki/Landau's_problems

    Chen's theorem, another weakening of Goldbach's conjecture, proves that for all sufficiently large n, = + where p is prime and q is either prime or semiprime. [note 1] Bordignon, Johnston, and Starichkova, [5] correcting and improving on Yamada, [6] proved an explicit version of Chen's theorem: every even number greater than , is the sum of a ...

  6. List of Mersenne primes and perfect numbers - Wikipedia

    en.wikipedia.org/wiki/List_of_Mersenne_primes...

    Perfect numbers are natural numbers that equal the sum of their positive proper divisors, which are divisors excluding the number itself. So, 6 is a perfect number because the proper divisors of 6 are 1, 2, and 3, and 1 + 2 + 3 = 6. [2] [4] Euclid proved c. 300 BCE that every prime expressed as M p = 2 p − 1 has a corresponding perfect number ...

  7. Formula for primes - Wikipedia

    en.wikipedia.org/wiki/Formula_for_primes

    However, it does not contain all the prime numbers, since the terms gcd(n + 1, a n) are always odd and so never equal to 2. 587 is the smallest prime (other than 2) not appearing in the first 10,000 outcomes that are different from 1. Nevertheless, in the same paper it was conjectured to contain all odd primes, even though it is rather inefficient.

  8. Dress Codes: How did plaid become popular for school uniforms?

    www.aol.com/dress-codes-did-plaid-become...

    By the 1990s, the styles were no longer just available by contracted uniform companies, either, Maxwell noted, as stores like Gap and The Children’s Place stocked up on plaid skirts and jumpers.

  9. Regular prime - Wikipedia

    en.wikipedia.org/wiki/Regular_prime

    An odd prime number p is defined to be regular if it does not divide the class number of the pth cyclotomic field Q(ζ p), where ζ p is a primitive pth root of unity. The prime number 2 is often considered regular as well. The class number of the cyclotomic field is the number of ideals of the ring of integers Z(ζ p) up to equivalence.