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Sparsely Totient Number
In mathematics, a sparsely totient number is a certain kind of natural number. A natural number, ''n'', is sparsely totient if for all ''m'' > ''n'', :\varphi(m)>\varphi(n) where \varphi is Euler's totient function. The first few sparsely totient numbers are: 2, 6, 12, 18, 30, 42, 60, 66, 90, 120, 126, 150, 210, 240, 270, 330, 420, 462, 510, 630, 660, 690, 840, 870, 1050, 1260, 1320, 1470, 1680, 1890, 2310, 2730, 2940, 3150, 3570, 3990, 4620, 4830, 5460, 5610, 5670, 6090, 6930, 7140, 7350, 8190, 9240, 9660, 9870, ... . The concept was introduced by David Masser and Peter Man-Kit Shiu in 1986. As they showed, every primorial is sparsely totient. Properties * If ''P''(''n'') is the largest prime factor A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ... of ''n'', th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
126 (number)
126 (one hundred ndtwenty-six) is the natural number following 125 and preceding 127. In mathematics As the binomial coefficient \tbinom, 126 is a central binomial coefficient and a pentatope number. It is also a decagonal number, a Harshad number and a pentagonal pyramidal number. As 125 + 1 it is σ3(5), the fifth value of the sum of cubed divisors function, and is a sum of two cubes. There are exactly 126 crossing points among the diagonals of a regular nonagon, 126 binary strings of length seven that are not repetitions of a shorter string, 126 different semigroups on four elements (up to isomorphism and reversal), and 126 different ways to partition a decagon into even polygons by diagonals. There are exactly 126 positive integers that are not solutions of the equation :x=abc+abd+acd+bcd, where ''a'', ''b'', ''c'', and ''d'' must themselves all be positive integers. It is the fifth Granville number, and the third such not to be a perfect number. Also, it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primorial
In mathematics, and more particularly in number theory, primorial, denoted by "#", is a function from natural numbers to natural numbers similar to the factorial function, but rather than successively multiplying positive integers, the function only multiplies prime numbers. The name "primorial", coined by Harvey Dubner, draws an analogy to ''primes'' similar to the way the name "factorial" relates to ''factors''. Definition for prime numbers For the th prime number , the primorial is defined as the product of the first primes: :p_n\# = \prod_^n p_k, where is the th prime number. For instance, signifies the product of the first 5 primes: :p_5\# = 2 \times 3 \times 5 \times 7 \times 11 = 2310. The first five primorials are: : 2, 6, 30, 210, 2310 . The sequence also includes as empty product. Asymptotically, primorials grow according to: :p_n\# = e^, where is Little O notation. Definition for natural numbers In general, for a positive integer , its pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Man-Kit Shiu
Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a surname (including a list of people with the name) Culture * Peter (actor) (born 1952), stage name Shinnosuke Ikehata, Japanese dancer and actor * ''Peter'' (album), a 1993 EP by Canadian band Eric's Trip * ''Peter'' (1934 film), a 1934 film directed by Henry Koster * ''Peter'' (2021 film), Marathi language film * "Peter" (''Fringe'' episode), an episode of the television series ''Fringe'' * ''Peter'' (novel), a 1908 book by Francis Hopkinson Smith * "Peter" (short story), an 1892 short story by Willa Cather Animals * Peter, the Lord's cat, cat at Lord's Cricket Ground in London * Peter (chief mouser), Chief Mouser between 1929 and 1946 * Peter II (cat), Chief Mouser between 1946 and 1947 * Peter III (cat), Chief Mouser between 1947 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Masser
David William Masser (born 8 November 1948) is Professor Emeritus in the Department of Mathematics and Computer Science at the University of Basel. He is known for his work in transcendental number theory, Diophantine approximation, and Diophantine geometry. With Joseph Oesterlé in 1985, Masser formulated the abc conjecture, which has been called "the most important unsolved problem in Diophantine analysis".. Early life and education Masser was born on 8 November 1948 in London, England. He graduated from Trinity College, Cambridge with a B.A. (Hons) in 1970. In 1974, he obtained his M.A. and Ph.D. at the University of Cambridge, with a doctoral thesis under the supervision of Alan Baker titled ''Elliptic Functions and Transcendence''. Career Masser was a Lecturer at the University of Nottingham from 1973 to 1975, before spending the 1975-1976 year as a Research Fellow of Trinity College at the University of Cambridge. He returned to the University of Nottingham to serve as a L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
420 (number)
420 (four hundred ndtwenty) is the natural number following 419 and preceding 421. In mathematics 420 is: *the sum of four consecutive primes (101 + 103 + 107 + 109). *the sum of the first 20 positive even numbers. *a zero of the Mertens function and is sparsely totient. *a pronic number. *the smallest number divisible by the numbers 1 to 7, and as a consequence of that it is a Harshad number in every base from 2 to 10 except base 5. *a 141- gonal number. *a balanced number. In other fields *420 is a slang term that refers to the consumption of cannabis. April 20th is commonly celebrated as a holiday dedicated to the drug, due to the numerical form of the day being 4/20. *420 is the country calling code for Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The .... R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
330 (number)
300 (three hundred) is the natural number following 299 and preceding 301. Mathematical properties The number 300 is a triangular number and the sum of a pair of twin primes (149 + 151), as well as the sum of ten consecutive primes (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47). It is palindromic in 3 consecutive bases: 30010 = 6067 = 4548 = 3639, and also in base 13. Factorization is 30064 + 1 is prime Other fields Three hundred is: * In bowling, a perfect score, achieved by rolling strikes in all ten frames (a total of twelve strikes) * The lowest possible Fair Isaac credit score * Three hundred ft/s is the maximum legal speed of a shot paintball * In the Hebrew Bible, the size of the military force deployed by the Israelite judge Gideon against the Midianites () * According to Islamic tradition, 300 is the number of ancient Israeli king Thalut's soldiers victorious against Goliath's soldiers * According to Herodotus, 300 is the number of ancient Spar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
270 (number)
270 (two hundred ndseventy) is the natural number following 269 and preceding 271. In mathematics *270 is a harmonic divisor number *270 is the fourth number that is divisible by its average integer divisor *270 is a practical number, by the second definition *The sum of the coprime counts for the first 29 integers is 270 *270 is a sparsely totient number, the largest integer with 72 as its totient *Given 6 elements, there are 270 square permutations *10! has 270 divisors *270 is a Harshad number in base 10 *270 is the smallest positive integer that has divisors ending by digits 1, 2, ..., 9. *270 is the smallest sum of a set of even numbers that contain every digit once. In other fields *The year 270 BC *The year 270 AD *The caliber of the .270 Winchester rifle *The number of U.S. Electoral College votes needed to be elected President of the United States *The average number of days in human pregnancy Integers from 271 to 279 271 272 272 = 24·17, sum of four consecutiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
240 (number)
240 (two hundred ndforty) is the natural number following 239 and preceding 241. In mathematics 240 is: *a semiperfect number. *a concatenation of two of its proper divisors. *a highly composite number since it has 20 divisors total (1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120, and 240), more than any previous number. *a refactorable number or tau number, since it has 20 divisors and 20 divides 240. *a highly totient number, since it has 31 totient answers, more than any previous integer. *a pronic number since it can be expressed as the product of two consecutive integers, 15 and 16. *palindromic in bases 19 (CC19), 23 (AA23), 29 (8829), 39 (6639), 47 (5547) and 59 (4459). *a Harshad number in bases 2, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15 (and 73 other bases). *the aliquot sum of 120 and 57121. *part of the 12161-aliquot tree. The aliquot sequence starting at 120 is: 120, 240, 504, 1056, 1968, 3240, 7650, 14112, 32571, 27333, 12161, 1, 0. 240 is the sm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
210 (number)
210 (two hundred [and] ten) is the natural number following 209 (number), 209 and preceding 211 (number), 211. In mathematics 210 is a composite number, an abundant number, Harshad number, and the product of the first four prime numbers (2 (number), 2, 3 (number), 3, 5 (number), 5, and 7 (number), 7), and thus a primorial. It is also the least common multiple of these four prime numbers. It is the sum of eight consecutive prime numbers (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 = 210).Wells, D. (1987). ''The Penguin Dictionary of Curious and Interesting Numbers'' (p. 143). London: Penguin Group. It is a triangular number (following 190 (number), 190 and preceding 231 (number), 231), a pentagonal number (following 176 (number), 176 and preceding 247 (number), 247), and the second smallest to be both triangular and pentagonal (the third is 40755). It is also an idoneal number, a pentatope number, a pronic number, and an untouchable number. 210 is also the third polygonal number, 71-g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
150 (number)
150 (one hundred ndfifty) is the natural number following 149 and preceding 151. In mathematics *150 is the sum of eight consecutive primes (7 + 11 + 13 + 17 + 19 + 23 + 29 + 31). Given 150, the Mertens function returns 0. *150 is conjectured to be the only minimal difference greater than 1 of any increasing arithmetic progression of n primes (in this case, n = 7) that is not a primorial (a product of the first m primes). *The sum of Euler's totient function φ(''x'') over the first twenty-two integers is 150. *150 is a Harshad number and an abundant number. *150 degrees is the measure of the internal angle of a regular dodecagon. In the Bible * The last numbered Psalm in the Bible, Psalm 150, considered the one most often set to music. * The number of sons of Ulam, who were combat archers, in the Census of the men of Israel upon return from exile (I Chronicles 8:40) * In the Book of Genesis, the number of days the waters from the Great Flood persisted on the Earth befor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
120 (number)
120, read as one hundred ndtwenty, is the natural number following 119 and preceding 121. In the Germanic languages, the number 120 was also formerly known as "one hundred". This "hundred" of six score is now obsolete, but is described as the long hundred or great hundred in historical contexts. In mathematics 120 is * the factorial of 5 i.e. 5 × 4 × 3 × 2 × 1 * the fifteenth triangular number, as well as the sum of the first eight triangular numbers, making it also a tetrahedral number. 120 is the smallest number to appear six times in Pascal's triangle (as all triangular and tetragonal numbers appear in it). Because 15 is also triangular, 120 is a doubly triangular number. 120 is divisible by the first 5 triangular numbers and the first 4 tetrahedral numbers. It is the eighth hexagonal number. * highly composite, superior highly composite, superabundant, and colossally abundant number, with its 16 divisors being more than any number lower than it has, and it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
