enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Bell number - Wikipedia

    en.wikipedia.org/wiki/Bell_number

    The triangular array whose right-hand diagonal sequence consists of Bell numbers. The Bell numbers can easily be calculated by creating the so-called Bell triangle, also called Aitken's array or the Peirce triangle after Alexander Aitken and Charles Sanders Peirce. [ 6 ] Start with the number one.

  3. Ordered Bell number - Wikipedia

    en.wikipedia.org/wiki/Ordered_Bell_number

    The figure shows the 13 weak orderings on three elements. Starting from , the ordered Bell numbers are. 1, 1, 3, 13, 75, 541, 4683, 47293, 545835, 7087261, 102247563, ... (sequence A000670 in the OEIS). When the elements to be ordered are unlabeled (only the number of elements in each tied set matters, not their identities) what remains is a ...

  4. Bell polynomials - Wikipedia

    en.wikipedia.org/wiki/Bell_polynomials

    The sum of the subscripts in a monomial is equal to the total number of elements. Thus, the number of monomials that appear in the partial Bell polynomial is equal to the number of ways the integer n can be expressed as a summation of k positive integers. This is the same as the integer partition of n into k parts. For instance, in the above ...

  5. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    List of chemical elements - Wikipedia. List of chemical elements. 118 chemical elements have been identified and named officially by IUPAC. A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ]

  6. Modular arithmetic - Wikipedia

    en.wikipedia.org/wiki/Modular_arithmetic

    Primitive root modulo m: A number g is a primitive root modulo m if, for every integer a coprime to m, there is an integer k such that g k ≡ a (mod m). A primitive root modulo m exists if and only if m is equal to 2, 4, p k or 2p k, where p is an odd prime number and k is a positive integer.

  7. Dirichlet character - Wikipedia

    en.wikipedia.org/wiki/Dirichlet_character

    Dirichlet character. In analytic number theory and related branches of mathematics, a complex-valued arithmetic function is a Dirichlet character of modulus (where is a positive integer) if for all integers and : [1] that is, is completely multiplicative. ; that is, is periodic with period .

  8. Normal distribution - Wikipedia

    en.wikipedia.org/wiki/Normal_distribution

    Probability theory. In probability theory and statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is The parameter is the mean or expectation of the distribution (and also its median and mode), while ...

  9. Partition of a set - Wikipedia

    en.wikipedia.org/wiki/Partition_of_a_set

    The Bell numbers are repeated along both sides of this triangle. The numbers within the triangle count partitions in which a given element is the largest singleton. The number of partitions of an n-element set into exactly k (non-empty) parts is the Stirling number of the second kind S(n, k). The number of noncrossing partitions of an n-element ...