enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Goldbach's weak conjecture - Wikipedia

    en.wikipedia.org/wiki/Goldbach's_weak_conjecture

    For if every even number greater than 4 is the sum of two odd primes, adding 3 to each even number greater than 4 will produce the odd numbers greater than 7 (and 7 itself is equal to 2+2+3). In 2013, Harald Helfgott released a proof of Goldbach's weak conjecture. [ 2 ]

  3. Four fours - Wikipedia

    en.wikipedia.org/wiki/Four_fours

    There is one table for each number n of occurrences of d. For example, when d=4, the hash table for two occurrences of d would contain the key-value pair 8 and 4+4, and the one for three occurrences, the key-value pair 2 and (4+4)/4 (strings shown in bold).

  4. List of integer sequences - Wikipedia

    en.wikipedia.org/wiki/List_of_integer_sequences

    The number of binary rooted trees (every node has ... A natural number n that is equal to the sum of all ... 8, 9, 10, 12, ... A Harshad number in base 10 is an ...

  5. Lehmer code - Wikipedia

    en.wikipedia.org/wiki/Lehmer_code

    By contrast the encodings considered here choose the first number from a set of n values, the next number from a fixed set of n − 1 values, and so forth decreasing the number of possibilities until the last number for which only a single fixed value is allowed; every sequence of numbers chosen from these sets encodes a single permutation.

  6. List of mathematical functions - Wikipedia

    en.wikipedia.org/wiki/List_of_mathematical_functions

    Step function: A finite linear combination of indicator functions of half-open intervals. Heaviside step function: 0 for negative arguments and 1 for positive arguments. The integral of the Dirac delta function. Sawtooth wave; Square wave; Triangle wave; Rectangular function; Floor function: Largest integer less than or equal to a given number.

  7. Twelvefold way - Wikipedia

    en.wikipedia.org/wiki/Twelvefold_way

    Rather, as explained under combinations, the number of n-multicombinations from a set with x elements can be seen to be the same as the number of n-combinations from a set with x + n − 1 elements. This reduces the problem to another one in the twelvefold way, and gives as result

  8. List of mathematical constants - Wikipedia

    en.wikipedia.org/wiki/List_of_mathematical_constants

    A mathematical constant is a key number whose value is fixed by an unambiguous definition, often referred to by a symbol (e.g., an alphabet letter), or by mathematicians' names to facilitate using it across multiple mathematical problems. [1]

  9. Legendre's three-square theorem - Wikipedia

    en.wikipedia.org/wiki/Legendre's_three-square...

    Pierre de Fermat gave a criterion for numbers of the form 8a + 1 and 8a + 3 to be sums of a square plus twice another square, but did not provide a proof. [1] N. Beguelin noticed in 1774 [ 2 ] that every positive integer which is neither of the form 8 n + 7, nor of the form 4 n , is the sum of three squares, but did not provide a satisfactory ...