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203 (number)
203 (two hundred ndthree) is the natural number following 202 and preceding 204. In mathematics 203 is the seventh Bell number, giving the number of partitions of a set of size 6. 203 different triangles can be made from three rods with integer lengths of at most 12, and 203 integer squares (not necessarily of unit size) can be found in a staircase-shaped polyomino formed by stacks of unit squares of heights ranging from 1 to 12. In other fields * 203 is the HTTP status code indicating non-authoritative information. ietf.org, retrieved 2014-07-26. See also * |
Natural Number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country"). Numbers used for counting are called ''Cardinal number, cardinal numbers'', and numbers used for ordering are called ''Ordinal number, ordinal numbers''. Natural numbers are sometimes used as labels, known as ''nominal numbers'', having none of the properties of numbers in a mathematical sense (e.g. sports Number (sports), jersey numbers). Some definitions, including the standard ISO/IEC 80000, ISO 80000-2, begin the natural numbers with , corresponding to the non-negative integers , whereas others start with , corresponding to the positive integers Texts that exclude zero from the natural numbers sometimes refer to the natural numbers together with zero as the whole numbers, while in other writings, that term is used instead for the integers (including negative integers). The natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
202 (number)
202 (two hundred ndtwo) is the natural number following 201 and preceding 203. In mathematics 202 is a Smith number, meaning that its digit sum and the sum of digits of its prime factors are equal. It is also a strobogrammatic number, meaning that when shown on a seven-segment display, turning the display upside-down shows the same number. There are exactly 202 partitions of 32 (a power of two) into smaller powers of two. There are also 202 distinct (non-congruent) polygons that can be formed by connecting all eight vertices of a regular octagon into a cycle, and 202 distinct (non-isomorphic) directed graphs on four unlabeled vertices, not having any isolated vertices. See also * Area code 202, the area code assigned to Washington D.C. * HTTP status code 202 meaning the request was accepted but has not yet been fulfilled * List of highways numbered 202 * The Peugeot 202 automobile * Potassium sorbate, a preservative whose E number E numbers ("E" stands for "Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
204 (number)
204 (two hundred ndfour) is the natural number following 203 and preceding 205. In mathematics 204 is a refactorable number. 204 is a square pyramidal number: 204 balls may be stacked in a pyramid whose base is an 8 × 8 square. Its square, 2042 = 41616, is the fourth square triangular number. As a figurate number, 204 is also a nonagonal number and a truncated triangular pyramid number. 204 is a member of the Mian-Chowla sequence. There are exactly 204 irreducible quintic polynomials over a four-element field, exactly 204 ways to place three non-attacking chess queens on a 5 × 5 board, exactly 204 squares of an infinite chess move that are eight knight's moves from the center, exactly 204 strings of length 11 over a three-letter alphabet with no consecutively-repeated substring, and exactly 204 ways of immersing an oriented circle into the oriented plane so that it has four double points. Both 204 and its square are sums of a pair of twin p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Number
In combinatorial mathematics, the Bell numbers count the possible partitions of a set. These numbers have been studied by mathematicians since the 19th century, and their roots go back to medieval Japan. In an example of Stigler's law of eponymy, they are named after Eric Temple Bell, who wrote about them in the 1930s. The Bell numbers are denoted B_n, where n is an integer greater than or equal to zero. Starting with B_0 = B_1 = 1, the first few Bell numbers are :1, 1, 2, 5, 15, 52, 203, 877, 4140, ... . The Bell number B_n counts the number of different ways to partition a set that has exactly n elements, or equivalently, the number of equivalence relations on it. B_n also counts the number of different rhyme schemes for n -line poems. As well as appearing in counting problems, these numbers have a different interpretation, as moments of probability distributions. In particular, B_n is the n -th moment of a Poisson distribution with mean 1. Counting Set partitions In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partition Of A Set
In mathematics, a partition of a set is a grouping of its elements into non-empty subsets, in such a way that every element is included in exactly one subset. Every equivalence relation on a set defines a partition of this set, and every partition defines an equivalence relation. A set equipped with an equivalence relation or a partition is sometimes called a setoid, typically in type theory and proof theory. Definition and Notation A partition of a set ''X'' is a set of non-empty subsets of ''X'' such that every element ''x'' in ''X'' is in exactly one of these subsets (i.e., ''X'' is a disjoint union of the subsets). Equivalently, a family of sets ''P'' is a partition of ''X'' if and only if all of the following conditions hold: *The family ''P'' does not contain the empty set (that is \emptyset \notin P). *The union of the sets in ''P'' is equal to ''X'' (that is \textstyle\bigcup_ A = X). The sets in ''P'' are said to exhaust or cover ''X''. See also collectively exhaus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyomino
A polyomino is a plane geometric figure formed by joining one or more equal squares edge to edge. It is a polyform whose cells are squares. It may be regarded as a finite subset of the regular square tiling. Polyominoes have been used in popular puzzles since at least 1907, and the enumeration of pentominoes is dated to antiquity. Many results with the pieces of 1 to 6 squares were first published in ''Fairy Chess Review'' between the years 1937 to 1957, under the name of "dissection problems." The name ''polyomino'' was invented by Solomon W. Golomb in 1953, and it was popularized by Martin Gardner in a November 1960 "Mathematical Games" column in ''Scientific American''. Related to polyominoes are polyiamonds, formed from equilateral triangles; polyhexes, formed from regular hexagons; and other plane polyforms. Polyominoes have been generalized to higher dimensions by joining cubes to form polycubes, or hypercubes to form polyhypercubes. In statistical physics, the study ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP Status Code
This is a list of Hypertext Transfer Protocol (HTTP) response status codes. Status codes are issued by a server in response to a client's request made to the server. It includes codes from IETF Request for Comments (RFCs), other specifications, and some additional codes used in some common applications of the HTTP. The first digit of the status code specifies one of five standard classes of responses. The optional message phrases shown are typical, but any human-readable alternative may be provided, or none at all. Unless otherwise stated, the status code is part of the HTTP standard (). The Internet Assigned Numbers Authority (IANA) maintains the official registry of HTTP status codes. All HTTP response status codes are separated into five classes or categories. The first digit of the status code defines the class of response, while the last two digits do not have any classifying or categorization role. There are five classes defined by the standard: * ''1xx informational re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 203
Area codes 203 and 475 are telephone area codes in the North American Numbering Plan The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international callin ... (NANP) for the southwestern part of the U.S. state of Connecticut. The numbering plan area (NPA) is mostly coextensive with the Connecticut portion of the New York metropolitan area, and comprises most of Fairfield County, Connecticut, Fairfield County, all of New Haven County, Connecticut, New Haven County, and a small portion of Litchfield County, Connecticut, Litchfield County. When the American Telephone and Telegraph Company (AT&T) established the first nationwide telephone numbering plan, numbering plan in 1947, Connecticut received only a single area code, 203, of the 86 original North American area codes. On August 28, 1995 the state was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siege Of Port Arthur
The siege of Port Arthur ( ja, 旅順攻囲戦, ''Ryojun Kōisen''; russian: link=no, Оборона Порт-Артура, ''Oborona Port-Artura'', August 1, 1904 – January 2, 1905) was the longest and most violent land battle of the Russo-Japanese War. Port Arthur, the deep-water port and Russian naval base at the tip of the Liaodong Peninsula in Manchuria, had been widely regarded as one of the most strongly fortified positions in the world. However, during the First Sino-Japanese War, General Nogi Maresuke had taken the city from the forces of Qing China in only a few days. The ease of his victory during the previous conflict, and overconfidence by the Japanese General Staff in its ability to overcome improved Russian fortifications, led to a much longer campaign and far greater losses than expected. The siege of Port Arthur saw the introduction of much technology used in subsequent wars of the 20th century (particularly in World War I) including massive 28 cm howit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lüshunkou District
Lüshunkou District (also Lyushunkou District; ) is a district of Dalian, Liaoning province, China. Also formerly called Lüshun City () or literally Lüshun Port (), it was formerly known as both Port Arthur (russian: Порт-Артур, translit=Port-Artur) and Ryojun ( ja, 旅順). The district's area is and its permanent population is 324,773. Lüshunkou is located at the extreme southern tip of the Liaodong Peninsula. It has an excellent natural harbor, the possession and control of which became a '' casus belli'' of the Russo-Japanese War (1904–05). Japanese and then Russian administration was established in 1895 and continued until 1905 when control was ceded to Japan. During that period, it was world-famous and was more significant than the other port on the peninsula, Dalian proper. Toponym In English-language diplomatic, news, and historical writings, it was known as Port Arthur after a British Royal Navy Lieutenant named William Arthur who surveyed the harbor i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
