There are instances when certain random observations by ingenious mathematicians bordered on subtle form of humour. The conversation between Srinivasa Ramanujan,
the Indian mathematician and G H Hardy, the Cambridge mathematician, produced such a quip while the former was in hospital bed
in Putney, West London in the early 20th
century. 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."
1729 = 13
The story of mathematical humour - this is not the end...