Comments on: Some numbers are more famous than others

By: Jan Nordgreen

Jan Nordgreen — Thu, 25 Jun 2009 15:07:20 +0000

1729 is known as the Hardy–Ramanujan number after a famous anecdote of the British mathematician G. H. Hardy regarding a hospital visit to the Indian mathematician Srinivasa Ramanujan. In Hardy’s words:

“I remember once going to see him when he was ill at Putney. 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. “No,” he replied, “it is a very interesting number; it is the smallest number expressible as the sum of two cubes in two different ways.”

Taken from the Wikipedia link above.

By: Michael Maguire

Michael Maguire — Thu, 25 Jun 2009 14:38:54 +0000

The link is messed up. Sorry — you’ll need to copy / paste the full url for wikipedia to come up with anything.

By: Michael Maguire

Michael Maguire — Thu, 25 Jun 2009 14:37:55 +0000

In trying to answer why this is a famous number, I googled “1729″ and found this page: http://en.wikipedia.org/wiki/1729_(number). As far as I can tell, 1729 seems to only be famous for the property noted in this forum.

By: Michael Maguire

Michael Maguire — Thu, 25 Jun 2009 14:29:13 +0000

1³+12³=9³+10³

By: jannordgreen

jannordgreen — Thu, 25 Jun 2009 04:53:46 +0000

What is the answer to the puzzle if ‘cubes’ have to be taken from the set 1, 8, 27, 64, …?

By: Richard Sabey

Richard Sabey — Thu, 25 Jun 2009 04:39:50 +0000

Ah, well, in that case,

3 = (cube root of 3)³ + 0³ = (cube root of 2)³ + 1³.

By: Nick

Nick — Wed, 24 Jun 2009 18:41:18 +0000

91 = 3³ + 4³ = (-5)³ + 6³.

It’s famous as a counterexample to this puzzle.