Search results
Results From The WOW.Com Content Network
The main purpose of the combinatorial number system is to provide a representation, each by a single number, of all possible k -combinations of a set S of n elements. Choosing, for any n, {0, 1, ..., n − 1 } as such a set, it can be arranged that the representation of a given k -combination C is independent of the value of n (although n must ...
A list of articles about numbers (not about numerals). Topics include powers of ten, notable integers, prime and cardinal numbers, and the myriad system.
Some sequences have alternate names: 4n+1 are Pythagorean primes, 4n+3 are the integer Gaussian primes, and 6n+5 are the Eisenstein primes (with 2 omitted). The classes 10n+d (d = 1, 3, 7, 9) are primes ending in the decimal digit d.
Goldbach's conjecture is one of the oldest and best-known unsolved problems in number theory and all of mathematics. It states that every even natural number greater than 2 is the sum of two prime numbers. The conjecture has been shown to hold for all integers less than 4 × 10 18 but remains unproven despite considerable effort.
A ternary / ˈtɜːrnəri / numeral system (also called base 3 or trinary) has three as its base. Analogous to a bit, a ternary digit is a trit ( tri nary dig it ). One trit is equivalent to log 2 3 (about 1.58496) bits of information . Although ternary most often refers to a system in which the three digits are all non–negative numbers ...
All other four-digit numbers eventually reach 6174 if leading zeros are used to keep the number of digits at 4. For numbers with three identical digits and a fourth digit that is one higher or lower (such as 2111), it is essential to treat 3-digit numbers with a leading zero; for example: 2111 – 1112 = 0999; 9990 – 999 = 8991; 9981 – 1899 ...
These combinations (subsets) are enumerated by the 1 digits of the set of base 2 numbers counting from 0 to 2 n − 1, where each digit position is an item from the set of n. Given 3 cards numbered 1 to 3, there are 8 distinct combinations ( subsets ), including the empty set :
A powerful number is a positive integer m such that for every prime number p dividing m, p2 also divides m. Equivalently, a powerful number is the product of a square and a cube, that is, a number m of the form m = a2b3, where a and b are positive integers (in some cases, the cube is 1). Powerful numbers are also known as squareful, square-full ...