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185 (number)
185 (one hundred ndeighty-five) is the natural number following 184 and preceding 186. In mathematics There are 185 different directed graphs on four unlabeled vertices that have at least one sink vertex, with no outgoing edges, 185 ways of permuting the squares of a 2\times 4 grid of squares in such a way that each square is one unit away from its original position horizontally, vertically, or diagonally, and 185 matroids on five labeled elements in which each element participates in at least one basis. The Spiral of Theodorus is formed by unit-length line segments that, together with the center point of the spiral, form right triangles. 185 of these right triangles fit within the first four turns of this spiral. See also * The year AD 185 or 185 BC __NOTOC__ Year 185 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Pulcher and Puditanus (or, less frequently, year 569 '' Ab urbe condita''). The denomination 185 BC f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
184 (number)
184 (one hundred ndeighty-four) is the natural number following 183 and preceding 185. In mathematics There are 184 different Eulerian graphs on eight unlabeled vertices, and 184 paths by which a chess rook can travel from one corner of a 4 × 4 chessboard to the opposite corner without passing through the same square twice. 184 is also a refactorable number. In other fields Some physicists have proposed that 184 is a magic number for neutrons in atomic nuclei. In poker, with one or more jokers as wild cards, there are 184 different straight flushes. See also * The year AD 184 or 184 BC * List of highways numbered 184 The following highways are numbered 184: Ireland * R184 road (Ireland) Japan * Japan National Route 184 Poland * Voivodeship road 184 (Poland), Voivodeship road 184 United States * Interstate 184 * Alabama State Route 184 * Arkansas Highway ... * References {{DEFAULTSORT:184 (Number) Integers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
186 (number)
186 (one hundred ndeighty-six) is the natural number following 185 and preceding 187. In mathematics There is no integer with exactly 186 coprimes less than it, so 186 is a nontotient. It is also never the difference between an integer and the total of coprimes below it, so it is a noncototient In mathematics, a noncototient is a positive integer ''n'' that cannot be expressed as the difference between a positive integer ''m'' and the number of coprime integers below it. That is, ''m'' − φ(''m'') = ''n'', where .... There are 186 different pentahexes, shapes formed by gluing together five regular hexagons, when rotations of shapes are counted as distinct from each other. 186 is a Fine number. See also * The year AD 186 or 186 BC * List of highways numbered 186 * References {{DEFAULTSORT:186 (Number) Integers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directed Graph
In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph that is made up of a set of vertices connected by directed edges, often called arcs. Definition In formal terms, a directed graph is an ordered pair where * ''V'' is a set whose elements are called '' vertices'', ''nodes'', or ''points''; * ''A'' is a set of ordered pairs of vertices, called ''arcs'', ''directed edges'' (sometimes simply ''edges'' with the corresponding set named ''E'' instead of ''A''), ''arrows'', or ''directed lines''. It differs from an ordinary or undirected graph, in that the latter is defined in terms of unordered pairs of vertices, which are usually called ''edges'', ''links'' or ''lines''. The aforementioned definition does not allow a directed graph to have multiple arrows with the same source and target nodes, but some authors consider a broader definition that allows directed graphs to have such multiple arcs (namely, they allow the arc set to be a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matroid
In combinatorics, a branch of mathematics, a matroid is a structure that abstracts and generalizes the notion of linear independence in vector spaces. There are many equivalent ways to define a matroid axiomatically, the most significant being in terms of: independent sets; bases or circuits; rank functions; closure operators; and closed sets or flats. In the language of partially ordered sets, a finite matroid is equivalent to a geometric lattice. Matroid theory borrows extensively from the terminology of both linear algebra and graph theory, largely because it is the abstraction of various notions of central importance in these fields. Matroids have found applications in geometry, topology, combinatorial optimization, network theory and coding theory. Definition There are many equivalent ( cryptomorphic) ways to define a (finite) matroid.A standard source for basic definitions and results about matroids is Oxley (1992). An older standard source is Welsh (1976). See Brylawsk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Of Theodorus
In geometry, the spiral of Theodorus (also called ''square root spiral'', ''Einstein spiral'', ''Pythagorean spiral'', or ''Pythagoras's snail'') is a spiral composed of right triangles, placed edge-to-edge. It was named after Theodorus of Cyrene. Construction The spiral is started with an isosceles right triangle, with each leg having unit length. Another right triangle is formed, an automedian right triangle with one leg being the hypotenuse of the prior triangle (with length the square root of 2) and the other leg having length of 1; the length of the hypotenuse of this second triangle is the square root of 3. The process then repeats; the nth triangle in the sequence is a right triangle with the side lengths \sqrt and 1, and with hypotenuse \sqrt. For example, the 16th triangle has sides measuring 4=\sqrt, 1 and hypotenuse of \sqrt. History and uses Although all of Theodorus' work has been lost, Plato put Theodorus into his dialogue '' Theaetetus'', which tells of his work. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Triangle
A right triangle (American English) or right-angled triangle (British), or more formally an orthogonal triangle, formerly called a rectangled triangle ( grc, ὀρθόσγωνία, lit=upright angle), is a triangle in which one angle is a right angle (that is, a 90-degree angle), i.e., in which two sides are perpendicular. The relation between the sides and other angles of the right triangle is the basis for trigonometry. The side opposite to the right angle is called the ''hypotenuse'' (side ''c'' in the figure). The sides adjacent to the right angle are called ''legs'' (or ''catheti'', singular: ''cathetus''). Side ''a'' may be identified as the side ''adjacent to angle B'' and ''opposed to'' (or ''opposite'') ''angle A'', while side ''b'' is the side ''adjacent to angle A'' and ''opposed to angle B''. If the lengths of all three sides of a right triangle are integers, the triangle is said to be a Pythagorean triangle and its side lengths are collectively known as a ''Pythagor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
185 BC
__NOTOC__ Year 185 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Pulcher and Puditanus (or, less frequently, year 569 ''Ab urbe condita''). The denomination 185 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Republic * The Roman general Scipio Africanus and his brother Lucius are accused by Cato the Elder and his supporters of having received bribes from the late Seleucid king Antiochus III. Scipio defies his accusers, reminds the Romans of their debt to him, and retires to his country house at Liternum in Campania. However, Cato is successful in breaking the political influence of Lucius Scipio and Scipio Africanus. Egypt * The civil war between the northern and southern areas of Egypt ends with the arrest of Ankmachis by the Ptolemaic general Conanus. India * Pushyamitra Shung ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Highways Numbered 185
Route 185 or Highway 185 may refer to: Canada * Quebec Route 185 India * National Highway 185 (India) Ireland * R185 road (Ireland) Japan * Japan National Route 185 Poland * Voivodeship road 185 (Poland), Voivodeship road 185 United States * Interstate 185 (other), Interstate 185 * U.S. Route 185 (former) * Alabama State Route 185 * Arkansas Highway 185 * California State Route 185 * Connecticut Route 185 * Florida State Road 185 (former) * Georgia State Route 185 * Hawaii Route 185 * Illinois Route 185 * K-185 (Kansas highway) * Kentucky Route 185 * Maine State Route 185 * Maryland Route 185 * M-185 (Michigan highway) * Missouri Route 185 * New Jersey Route 185 * New Mexico State Road 185 * New York State Route 185 * Ohio State Route 185 * Pennsylvania Route 185 (former) * South Carolina Highway 185 * Tennessee State Route 185 * Texas State Highway 185 ** Texas State Highway Spur 185 ** Farm to Market Road 185 (Texas) ** Urban Road 185 (Texas, signed as Farm to M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
