The subjects examined in this book have a rich history dating back to euler and jacobi, and. Ramanujan hardy number 1729 hardy arrived in a cab numbered 1729 he commented that the number was uninteresting instantly ramanujan claimed that it was the smallest natural number which can be written as sum of cubes in 2 ways 18. Pdf the purpose of this paper is to introduce some of the contributions of srinivasa ramanujan to number theory. You should instantly see that one of the columns in this table is completely red. A taxicab number is the name given by mathematicians to a series of special numbers.
Ramanujan number is a number which can be expressed as sum of cubes of two numbers in different combinations. The number 1,729 is not one to make the average persons pulse race, but it is the subject of one of the most remarkable stories in the history of mathematics most of us learnt basic. Note that the integer r n is necessarily a prime number. The number has since become known as the hardyramanujan number, the second socalled taxicab number, defined as. In this book, we examine chapters 1015 in ramanujans second note. Dec 17, 2014 ramanujan hardy number 1729 hardy arrived in a cab numbered 1729 he commented that the number was uninteresting instantly ramanujan claimed that it was the smallest natural number which can be written as sum of cubes in 2 ways 18. Dec 24, 2005 that are the smallest number that can be expressed as the sum of two cubes in n distinct ways have been dubbed taxicab numbers. Ramanujan mathematical society, thiruchirappalli, tamil nadu, india. Ramanujans notebooks the history of the notebooks, in brief, is the following. The number was also found in one of ramanujans notebooks dated years. Ramanujans room, he quoted that he had just came in a taxi cab having number 1729 which seemed to him an unlucky number but at that time, he prayed that his perception may go wrong as he wanted that his friend would get well soon, but ramanujan promptly replied that this was a very interesting number as it is the smallest number which can be. The converse of this result is the definition of ramanujan primes. Library of congress cataloging in publication data.
The film, written and directed by gnana rajasekaran, was shot back to back in the tamil and english languages. Ramanujan is a 2014 biographical film based on the life of renowned indian mathematician srinivasa ramanujan. I had ridden in taxi cab number 1729 and remarked that the number seemed to me rather a dull one, and that i hoped it was not an unfavorable omen. When ramanujan was dying of tuberculosis in a hospital, g. It was ramanujan who discovered that it is the smallest number that can be expressed as the sum of two cubes in two different ways. Highly composite numbers 121 75, the number of representations of n by some other quadratic forms is considered, but no longer its maximal order. Hi, i have a programming assignment to display all the ramanujan numbers less than n in a table output. This was the number of the taxi cab hardy had taken to the clinic, and as befits two number theorists they discussed its significance. A ramanujan number is a number which is expressible as the sum of two cubes in two different ways.
Taxicab number simple english wikipedia, the free encyclopedia. One feels that ramanujan is ready to leave the subject of highly composite numbers, and to come back to another favourite topic, identities. Though he didnt had formal education in pure mathematics, he gave nearly 3500 results in theorems and mathematical identities. Ramanujans 1729 taxi number lends new discovery in mathematics. It is known as the hardyramanujan number, after an anecdote of the british mathematician g. A ramanujan prime is a prime number that satisfies a result proved by srinivasa ramanujan relating to the prime counting function. I remember once going to see him when he was ill at putney. Hardy was very superstitious due to his such nature when he entered into ramanujans room, he quoted that he had just came in a taxi cab having number 1729 which. Apr 28, 2016 some things you probably did not know about 1729 and the man who knew infinity. R n the first five ramanujan primes are thus 2, 11, 17, 29, and 41.
It is also called as hardyramanujan number, taxi number or ramanujan number. The hardyramanujan number 1729 cantors paradise medium. In this book, we examine chapters 1015 in ramanujans second note book. The number 1729 has acquired a special status in mathematics. Ramanujan gave the two positive cubes in two different ways. Ramanujan had no actual involvement with the number. He explained that it was the smallest number that could be expressed by the sum of two cubes in two different ways.
Apr 16, 2010 1729 is the natural number following 1728 and preceding 1730. In 1919, ramanujan published a new proof of bertrands postulate which, as he notes, was first proved by chebyshev. Hardy later told the nowfamous story that he once visited ramanujan at a nursing home, telling him that he came in a taxicab with number 1729, and saying that it seemed to him a rather dull. Ramanujan had noted down the results of his researches, without proofs, as in a synopsis of elementary results, a book on pure mathematics, by g. Highly composite numbers claude bernard university lyon 1.
It was ramanujan who discovered that it is the smallest number that can be expressed as the sum of. Srinivasa ramanujan was a great mathematician of india whose one of the famous invention was ramanujan number which is 1729. What is ramanujan number 1729 national mathematics. Ramanujan number 1729 pdf 1729 is the natural number following 1728 and preceding 1730. The nth ramanujan prime is the least integer r n for which. The smallest number that can be expressed as the sum of two cubes in n distinct ways. Take a look at this table of the numbers pn with n running from 0 up to 49, arranged in 10 rows of length 5. Ramanujan primes are the least integers r n for which there are at least n primes between x and x2 for all x. His father worked in kumbakonam as a clerk in a cloth merchants shop.
Ramanujan did not leave us proofs of the thousands of theorems he recorded in his notebooks, and so it cannot be claimed that many of the proofs given in this book are those found by ramanujan. The number was also found in one of ramanujan s notebooks dated years before the incident. The graph above shows the distribution of the first 100 ramanujan numbers 2way pairs in the number field. We all know very well about sri srinivasa ramanujan, one of the great indian mathematicians and his number 1729. One day, hardy visited ramanujan at the hospital as he regularly had before, stepping out of a black cab with the number 1729, rather a dull one, hardy said as he met ramanujan. The man who knew infinity ramanujan college of management. One day hardy went there by taxi, and said as his first remark, for want of a subject for conversation. The two different ways 1729 is expressible as the sum of two cubes are 1. Since then the number 1729 is called hardyramanujans number. Oct 16, 2015 how a rather dull taxi number inspired ramanujan to make a math discovery decades ahead of his time by 1918, the indian born, selfthought mathematical genius srinivasa ramanujan was already. A taxicab number is the smallest number that can be expressed as the sum of two positive cubes in n distinct ways.
He further added to hardys comment, that 1729 is not a dull number at all. Hardyramanujan number once hardy visited putney in a taxi cab having number 1729, where ramanujan was hospitalized. Hardy regarding a hospital visit to the indian mathematician srinivasa ramanujan. He must have thought about it a little because he entered the room where ramanujan lay in bed and, with scarcely a hello, blurted out his disappointment with it. On the occasion of the 125th birth anniversary of the famous indian mathematician srinivasa ramanujan, the tata institute. Media in category 1729 number the following 2 files are in this category, out of 2 total. Littlewood to speculate that ramanujan was friends with each of the.
Here now is the first book to provide an introduction to his work in number theory. The ramanujan constant is an extremely close almostinteger, equal to \\e\\pi\\sqrt163 \\approx 262,537,412,640,768,743. The indian mathematician srinivasa ramanujan 18871920 and the british. When ramanujan was a year old his mother took him to the town of kumbakonam, about 160 km nearer madras. Carr, in three notebooks, between the years 1903 1914, before he left for england.
It is the smallest number expressible as a sum of two cubes in two different ways. But, due to his love for numbers, ramanujan found something special about this number as well and said. An introduction to ramanujans magic squares georgep. Ramanujan numbers and the taxicab problem durango bills. The number 1729 is known as the hardyramanujan number after a famous visit by hardy to see ramanujan at a hospital.
Ive marked the numbers that are divisible by 5 with the color red. It is the smallest number expressible as the sum of two cubes in two different ways. Ramanujans astonishing knowledge of 1729 thatsmaths. Why 1729 a magic number is known as ramanujan number. Of these first 100 ramanujan numbers, 49 are primitive as they are not multiples of smaller solutions. Ramanujan replied no, it is a very interesting number. Ramanujan and mathematics in india texpoint fonts used in emf. Though he had almost no formal training in pure mathematics, he made substantial contributions to mathematical analysis, number theory, infinite series, and continued. Ramanujan replied that 1729 was not a boring number at all. Ramanujan was born in his grandmothers house in erode, a small village about 400 km southwest of madras. Ramanujan, in turn, replied that the taxi number 1729, was the smallest number that can be shown as the sum of two cubes two di erent ways. Apr 26, 2012 ramanujan number taxicab number hardy used to visit ramanujan, as he lay dying of tuberculosis in hospital at putney. He made mention of the number of the taxi that he was in, stating that it was such an uninteresting number.
At the end of the twopage published paper, ramanujan derived a generalized result. On the ramanujannagell equation and its generalizations. Most of ramanujans work in number theory arose out of \q\series and theta functions. Once, in the taxi from london, hardy noticed its number, 1729. If you mention the number 1729 or the phrase taxicab problem to any mathematician, it will immediately bring up the subject of the selftaught indian mathematical genius srinivasa ramanujan. Jul 15, 2007 the number 1729 is known as the ramunujan number.
The number derives its name from the following story g. Srinivasa ramanujan mathematician 1729 gh hardy what ive been doing all morning is that ive been trying to come up with some numerically interesting factoid about the number 125. Ramanujan is said to have stated on the spot that, on the contrary, it was actually a very interesting number mathematically, being the smallest number representable in two different ways as a sum of two cubes. This number is now called the hardyramanujan number, and the smallest numbers that can be expressed as the sum of two cubes in n different ways have been dubbed. Input input from keyboard, a positive integer n less than or equal to 1,000,000 output output to the screen a table of ramanujan numbers less than n with the corresponding pair of cubes, and the cube roots of these cubes. The number was also found in one of ramanujans notebooks dated years before the incident. In this video, a clock was prepared using the digits 1, 7, 2, 9 from ramanujan.
Hardi described the cabs number as boring, on which ramanujan immediately said, no, this is not a boring but a very interesting number. Why is the number 1729 known as the ramanujan number. Berndtspringer1985 theoriginofchapter1 probablyisfoundin ramanujansearlyschooldays andisthereforemuchearlierthan theremainderofthenotebooks. Input input from keyboard, a positive integer n less than or equal to 1,000,000output output to the screen a table of ramanujan numbers less than. Jun 16, 2016 the famous story of ramanujan and his instant recollection of a pretty property of the number 1729 which i wont repeat here, but is worth looking up if its unfamiliar to you led mathematician j. However, they are all in the spirit of his mathematics. It is 1729, found by mathemagician srinivas ramanujan, 1729 is said to be the enchantment number, since it is the sole number which can be communicated, as the entirety of sum. Number 1729, rather a dull number, ramanujan immediately.
Since then, 1729 is called hardyramanujan number in his honor. Visiting ramanujan in hospital, hardy remarked that the number of the taxi he had taken was 1729, which he thought to be rather dull. Ramanujans 1729 taxi number lends new discovery in. Ramanujansworkonmagicsquares ispresented,insomedetail,in chapter1pp. Most of ramanujan s work in number theory arose out of \q\series and theta functions. May 12, 2016 visiting ramanujan in hospital, hardy remarked that the number of the taxi he had taken was 1729, which he thought to be rather dull. Ramanujan studies and works with godfrey hardy 1916. The digits of the hardyramanujan number 1729 as 7 x 2 x 9 1 125. Ramanujan is elected fellow of the royal society f. The story begins like thisthe number derives its name from the following story g.
Hardy was very superstitious due to his such nature when he entered into ramanujans room, he quoted that he had just came in a taxi cab having number 1729 which seemed to him an unlucky number but at that time, he prayed that. Ramanujan the mathematics genius science page news. Ramanujan said, no, it is a very interesting number. This is the smallest number which can be written in the form of a sum of two cubes in two different ways. Pdf contributions of srinivasa ramanujan to number theory. Ramanujan is recognized as one of the great number theorists of the twentieth century. This is the smallest number that can be expressed as the sum of cubes. Srinivasa ramanujan was the renowned indian mathematician. The smallest number that can be expressed as the sum of two cubes in. Apr 26, 2018 the number derives its name from the following story g. It has nothing to do with taxis, but the name comes from a wellknown conversation that took place between two famous mathematicians. Ramanujan s notebooks the history of the notebooks, in brief, is the following. It is a taxicab number, and is variously known as the ramanujans number and the hardyramanujan number, after an anecdote of the british mathematician g. Proceedings of the first conference of the canadian number theory association held at the banff center, banff, alberta, april 1727.
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