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The Story Of Ramanujan’s Magic Number


The Ramanujan’s magic number is also known as Ramanujan and Hardy number. Ramanujan was a well renowned Indian mathematician. Godfrey H. Hardy was a British Mathematician. Hardy tutored Ramanujan and also collaborated with him in some research.


In a famous anecdote, Hardy once visited to see sick S. Ramanujan in hospital in Putney. When he got there, he told Ramanujan that the cab’s number, 1729, was “rather a dull one.” Ramanujan said, ‘No, Hardy it’s a very interesting number.

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It is the smallest number expressible as the sum of two positives’ cubes in two different ways.

1729 = 1^3+12^3 = 9^3+10^3.Image result for hardy ramanujan number

This number is now called Ramanujan’s Magic number. The smallest numbers that may be expressed because the sum of two cubes in n other ways are dubbed taxicab numbers(Ta, 2 =1729).

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This property of 1729 was mentioned in the film proof (2005) by the character Robert the sometimes-insane mathematician. This role was played by Anthony Hopkins. It was also part of the animated television series Futurama episode DVD 2ACV02 designation of the spaceship Nimbus BP-1729 appearing in Season 2. Also, the robot character Bender’s serial number, as portrayed in a Christmas card in the episode Xmas Story.

Hardy-Ramanujan Number -- from Wolfram MathWorld

Hardy came up with a scale of mathematical ability that went from 0 to 100. He put himself at 25. Hilbert, the German mathematician, was at 80. Ramanujan was 100.

Ramanujan died in 1920 at the age of 32. He left behind 3 notebooks & a sheaf of papers (the “lost notebook”).

These notebooks contained thousands of results that are still inspiring mathematical work decades later.



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