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1458 (number)
1458 is the integer after 1457 and before 1459. The maximum determinant of an 11 by 11 matrix of zeroes and ones is 1458. 1458 is one of three numbers which, when its base 10 digits are added together, produces a sum which, when multiplied by its reversed self, yields the original number: : 1 + 4 + 5 + 8 = 18 : 18 × 81 = 1458 The only other non-trivial numbers with this property are 81 and 1729, as well as the trivial solutions 1 and 0. It was proven by Masahiko Fujiwara Masahiko Fujiwara (Japanese: 藤原 正彦 ''Fujiwara Masahiko''; born July 9, 1943, in Shinkyo, Manchukuo) is a Japanese mathematician and writer who is known for his book '' The Dignity of the Nation''. He is a professor emeritus at Ochanomiz .... References {{DEFAULTSORT:1458 (Number) Integers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
81 (number)
81 (eighty-one) is the natural number following 80 and preceding 82. In mathematics 81 is: * the square of 9 and the fourth power of 3. * a perfect totient number like all powers of three. * a heptagonal number. * a centered octagonal number. * a tribonacci number. * an open meandric number. * the ninth member of the Mian-Chowla sequence. * a palindromic number in bases 8 (1218) and 26 (3326). * a Harshad number in bases 2, 3, 4, 7, 9, 10 and 13. * one of three non-trivial numbers (the other two are 1458 and 1729) which, when its digits (in decimal) are added together, produces a sum which, when multiplied by its reversed self, yields the original number: : 8 + 1 = 9 : 9 × 9 = 81 (although this case is somewhat degenerate, as the sum has only a single digit). The inverse of 81 is 0. recurring, missing only the digit "8" from the complete set of digits. This is an example of the general rule that, in base ''b'', :\frac = 0.\overline, omitting only the digit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1729 (number)
1729 is the natural number following 1728 and preceding 1730. It is a taxicab number, and is variously known as Ramanujan's number and the Ramanujan-Hardy number, after an anecdote of the British mathematician G. H. Hardy when he visited Indian mathematician Srinivasa Ramanujan in hospital. He related their conversation: The two different ways are: : 1729 = 13 + 123 = 93 + 103 The quotation is sometimes expressed using the term "positive cubes", since allowing negative perfect cubes (the cube of a negative integer) gives the smallest solution as 91 (which is a divisor of 1729; 1991 = 1729). :91 = 63 + (−5)3 = 43 + 33 Numbers that are the smallest number that can be expressed as the sum of two cubes in ''n'' distinct ways have been dubbed " taxicab numbers". The number was also found in one of Ramanujan's notebooks dated years before the incident, and was noted by Frénicle de Bessy in 1657. A commemorative plaque now appears at the site of the Ramanujan-Hardy incid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 (number)
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
0 (number)
0 (zero) is a number representing an empty quantity. In place-value notation such as the Hindu–Arabic numeral system, 0 also serves as a placeholder numerical digit, which works by multiplying digits to the left of 0 by the radix, usually by 10. As a number, 0 fulfills a central role in mathematics as the additive identity of the integers, real numbers, and other algebraic structures. Common names for the number 0 in English are ''zero'', ''nought'', ''naught'' (), ''nil''. In contexts where at least one adjacent digit distinguishes it from the letter O, the number is sometimes pronounced as ''oh'' or ''o'' (). Informal or slang terms for 0 include ''zilch'' and ''zip''. Historically, ''ought'', ''aught'' (), and ''cipher'', have also been used. Etymology The word ''zero'' came into the English language via French from the Italian , a contraction of the Venetian form of Italian via ''ṣafira'' or ''ṣifr''. In pre-Islamic time the word (Arabic ) had the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masahiko Fujiwara
Masahiko Fujiwara (Japanese: 藤原 正彦 ''Fujiwara Masahiko''; born July 9, 1943, in Shinkyo, Manchukuo) is a Japanese mathematician and writer who is known for his book '' The Dignity of the Nation''. He is a professor emeritus at Ochanomizu University. Biography Masahiko Fujiwara is the son of Jirō Nitta and Tei Fujiwara, who were both popular authors. He graduated from the University of Tokyo in 1966. He began writing after a two-year position as associate professor at the University of Colorado, with a book ''Wakaki sugakusha no Amerika'' designed to explain American campus life to Japanese people. He also wrote about the University of Cambridge, after a year's visit (''Harukanaru Kenburijji: Ichi sugakusha no Igirisu''). In a popular book on mathematics, he categorized theorems as beautiful theorems or ugly theorems. He is also known in Japan for speaking out against government reforms in secondary education. He wrote '' The Dignity of the Nation'', which according t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
