According to Hardy, he visited Ramanujan in a nursing home in 1918: "I
remember once going to see him when he was lying 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 unfavourable 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.'"
Their exchange can be unpacked and expressed as follows:
1,729 = 1³ + 12³ = 9³ + 10³
It is rare that a number can be split into two cubes, and even rarer that it can be split into two cubes in two different ways, and 1,729 is the smallest number that exhibits this property.
Their exchange can be unpacked and expressed as follows:
1,729 = 1³ + 12³ = 9³ + 10³
It is rare that a number can be split into two cubes, and even rarer that it can be split into two cubes in two different ways, and 1,729 is the smallest number that exhibits this property.
