enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Amicable numbers - Wikipedia

    en.wikipedia.org/wiki/Amicable_numbers

    In mathematics, the amicable numbers are two different natural numbers related in such a way that the sum of the proper divisors of each is equal to the other number. That is, s ( a )= b and s ( b )= a , where s ( n )=σ( n )- n is equal to the sum of positive divisors of n except n itself (see also divisor function ).

  3. Amenable number - Wikipedia

    en.wikipedia.org/wiki/Amenable_number

    (This generalizes the example of 5 given above.) Although not obvious from the definition, the set of amenable numbers is closed under multiplication (the product of two amenable numbers is an amenable number).

  4. Aliquot sequence - Wikipedia

    en.wikipedia.org/wiki/Aliquot_sequence

    The aliquot sequence starting with a positive integer k can be defined formally in terms of the sum-of-divisors function σ 1 or the aliquot sum function s in the following way: [1] = = = > = = = If the s n-1 = 0 condition is added, then the terms after 0 are all 0, and all aliquot sequences would be infinite, and we can conjecture that all aliquot sequences are convergent, the limit of these ...

  5. Sociable number - Wikipedia

    en.wikipedia.org/wiki/Sociable_number

    The period of the sequence, or order of the set of sociable numbers, is the number of numbers in this cycle. If the period of the sequence is 1, the number is a sociable number of order 1, or a perfect number—for example, the proper divisors of 6 are 1, 2, and 3, whose sum is again 6. A pair of amicable numbers is a set of sociable numbers of ...

  6. Amicable triple - Wikipedia

    en.wikipedia.org/wiki/Amicable_triple

    In mathematics, an amicable triple is a set of three different numbers so related that the restricted sum of the divisors of each is equal to the sum of other two numbers. [ 1 ] [ 2 ] In another equivalent characterization, an amicable triple is a set of three different numbers so related that the sum of the divisors of each is equal to the sum ...

  7. Betrothed numbers - Wikipedia

    en.wikipedia.org/wiki/Betrothed_numbers

    Quasi-sociable numbers or reduced sociable numbers are numbers whose aliquot sums minus one form a cyclic sequence that begins and ends with the same number. They are generalizations of the concepts of betrothed numbers and quasiperfect numbers. The first quasi-sociable sequences, or quasi-sociable chains, were discovered by Mitchell Dickerman ...

  8. Category:Lists of ambiguous numbers - Wikipedia

    en.wikipedia.org/wiki/Category:Lists_of...

    This category consists of titles that consist of numbers.. Use {{}} to add "ambiguous number" disambiguation pages to this category.. When other kinds of things are listed in the disambiguation page, then instead of {{numberdis}}, add {{disambiguation|number|...}} to the disambiguation page (with any other applicable disambiguation categories in additional parameters after |number; see ...

  9. 284 (number) - Wikipedia

    en.wikipedia.org/wiki/284_(number)

    284 is in the first pair of amicable numbers with 220. That means that the sum of the proper divisors are the same between the two numbers. [2] 284 can be written as a sum of exactly 4 nonzero perfect squares. [3] 284 is a nontotient number which are numbers where phi(x) equaling that number has no solution. [4] 284 is a number that is the nth ...