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14th Century In Cambodia
14 (fourteen) is a natural number following 13 and preceding 15. In relation to the word "four" ( 4), 14 is spelled "fourteen". In mathematics * 14 is a composite number. * 14 is a square pyramidal number. * 14 is a stella octangula number. * In hexadecimal, fourteen is represented as E * Fourteen is the lowest even ''n'' for which the equation φ(''x'') = ''n'' has no solution, making it the first even nontotient (see Euler's totient function). * Take a set of real numbers and apply the closure and complement operations to it in any possible sequence. At most 14 distinct sets can be generated in this way. ** This holds even if the reals are replaced by a more general topological space. See Kuratowski's closure-complement problem * 14 is a Catalan number. * Fourteen is a Companion Pell number. * According to the Shapiro inequality 14 is the least number ''n'' such that there exist ''x'', ''x'', ..., ''x'' such that :\sum_^ \frac < \frac where ''x'' = ''x' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetradecimal
There are many different numeral systems, that is, writing systems for expressing numbers. By culture / time period By type of notation Numeral systems are classified here as to whether they use positional notation (also known as place-value notation), and further categorized by radix or base. Standard positional numeral systems The common names are derived somewhat arbitrarily from a mix of Latin and Greek, in some cases including roots from both languages within a single name. There have been some proposals for standardisation. Non-standard positional numeral systems Bijective numeration Signed-digit representation Negative bases The common names of the negative base numeral systems are formed using the prefix ''nega-'', giving names such as: Complex bases Non-integer bases ''n''-adic number Mixed radix * Factorial number system * Even double factorial number system * Odd double factorial number system * Primorial number system * Fibonorial n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pell Number
In mathematics, the Pell numbers are an infinite sequence of integers, known since ancient times, that comprise the denominators of the closest rational approximations to the square root of 2. This sequence of approximations begins , , , , and , so the sequence of Pell numbers begins with 1, 2, 5, 12, and 29. The numerators of the same sequence of approximations are half the companion Pell numbers or Pell–Lucas numbers; these numbers form a second infinite sequence that begins with 2, 6, 14, 34, and 82. Both the Pell numbers and the companion Pell numbers may be calculated by means of a recurrence relation similar to that for the Fibonacci numbers, and both sequences of numbers grow exponentially, proportionally to powers of the silver ratio 1 + . As well as being used to approximate the square root of two, Pell numbers can be used to find square triangular numbers, to construct integer approximations to the right isosceles triangle, and to solve certain combinat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. Sulent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
