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Cayley's Mousetrap
Mousetrap is the name of a game introduced by the English mathematician Arthur Cayley. In the game, cards numbered 1 through n ("say thirteen" in Cayley's original article) are shuffled to place them in some random permutation and are arranged in a circle with their faces up. Then, starting with the first card, the player begins counting 1, 2, 3, ... and moving to the next card as the count is incremented. If at any point the player's current count matches the number on the card currently being pointed to, that card is removed from the circle and the player starts all over at 1 on the next card. If the player ever removes all of the cards from the permutation in this manner, then the player wins. If the player reaches the count n+1 and cards still remain, then the game is lost. In order for at least one card to be removed, the initial permutation of the cards must not be a derangement In combinatorial mathematics, a derangement is a permutation of the elements of a set, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English People
The English people are an ethnic group and nation native to England, who speak the English language, a West Germanic language, and share a common history and culture. The English identity is of Anglo-Saxon origin, when they were known in Old English as the ('race or tribe of the Angles'). Their ethnonym is derived from the Angles, one of the Germanic peoples who migrated to Great Britain around the 5th century AD. The English largely descend from two main historical population groups the West Germanic tribes (the Angles, Saxons, Jutes and Frisians) who settled in southern Britain following the withdrawal of the Romans, and the partially Romanised Celtic Britons already living there.Martiniano, R., Caffell, A., Holst, M. et al. Genomic signals of migration and continuity in Britain before the Anglo-Saxons. Nat Commun 7, 10326 (2016). https://doi.org/10.1038/ncomms10326 Collectively known as the Anglo-Saxons, they founded what was to become the Kingdom of England ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematical model, models, and mathematics#Calculus and analysis, change. History One of the earliest known mathematicians were Thales of Miletus (c. 624–c.546 BC); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem. The number of known mathematicians grew when Pythagoras of Samos (c. 582–c. 507 BC) established the Pythagoreans, Pythagorean School, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathemat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Cayley
Arthur Cayley (; 16 August 1821 – 26 January 1895) was a prolific British mathematician who worked mostly on algebra. He helped found the modern British school of pure mathematics. As a child, Cayley enjoyed solving complex maths problems for amusement. He entered Trinity College, Cambridge, where he excelled in Greek, French, German, and Italian, as well as mathematics. He worked as a lawyer for 14 years. He postulated the Cayley–Hamilton theorem—that every square matrix is a root of its own characteristic polynomial, and verified it for matrices of order 2 and 3. He was the first to define the concept of a group in the modern way—as a set with a binary operation satisfying certain laws. Formerly, when mathematicians spoke of "groups", they had meant permutation groups. Cayley tables and Cayley graphs as well as Cayley's theorem are named in honour of Cayley. Early years Arthur Cayley was born in Richmond, London, England, on 16 August 1821. His father, Hen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permutation
In mathematics, a permutation of a set is, loosely speaking, an arrangement of its members into a sequence or linear order, or if the set is already ordered, a rearrangement of its elements. The word "permutation" also refers to the act or process of changing the linear order of an ordered set. Permutations differ from combinations, which are selections of some members of a set regardless of order. For example, written as tuples, there are six permutations of the set , namely (1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), and (3, 2, 1). These are all the possible orderings of this three-element set. Anagrams of words whose letters are different are also permutations: the letters are already ordered in the original word, and the anagram is a reordering of the letters. The study of permutations of finite sets is an important topic in the fields of combinatorics and group theory. Permutations are used in almost every branch of mathematics, and in many other fields of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derangement
In combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element appears in its original position. In other words, a derangement is a permutation that has no fixed points. The number of derangements of a set of size ''n'' is known as the subfactorial of ''n'' or the ''n-''th derangement number or ''n-''th de Montmort number. Notations for subfactorials in common use include !''n,'' ''Dn'', ''dn'', or ''n''¡. For ''n'' > 0, the subfactorial !''n'' equals the nearest integer to ''n''!/''e,'' where ''n''! denotes the factorial of ''n'' and ''e'' is Euler's number. The problem of counting derangements was first considered by Pierre Raymond de Montmort in 1708; he solved it in 1713, as did Nicholas Bernoulli at about the same time. Example Suppose that a professor gave a test to 4 students – A, B, C, and D – and wants to let them grade each other's tests. Of course, no student should grade their own test. How many ways could t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Journal Of Combinatorics
European, or Europeans, or Europeneans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine European cuisine comprises the cuisines of Europe "European Cuisine." [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
