*I have never done anything useful. No discovery of mine has made or is likely to make, directly or indirectly, for good or for ill, the least difference to the amenity of the world. Judged by all practical standards, the value of my mathematical life is nil. And outside mathematics it is trivial anyhow. The case for my life then, or for anyone else who has been a mathematician in the same sense that I have been one is this: That I have added something to knowledge and helped others to add more, and that these somethings have a value that differ in degree only and not in kind from that of the creations of the great mathematicians or any of the other artists, great or small who’ve left some kind of memorial behind them. *

*I still say to myself when I am depressed and and find myself forced to listen to pompous and tiresome people “Well, I have done one thing you could never have done, and that is to have collaborated with Littlewood and Ramanujan on something like equal terms.” — G. H. Hardy (A Mathematician’s Apology)*

* The Indian Clerk* is a fictive biographical novel by David Leavitt, published in 2007. It is loosely based on the famous partnership between the Indian mathematician, Srinivasa Ramanujan, and his British mentor, the mathematician, G.H. Hardy.

The novel is inspired by the career of the self-taught mathematical genius Srinivasa Ramanujan, as seen mainly through the eyes of his mentor and collaborator G.H. Hardy, a British mathematics professor at Cambridge University. The narrative begins in January 1913, in Cambridge, England, where Hardy receives a letter filled with *unorthodox* but imaginative mathematics and asking for support and guidance.

I have found an old (1987) British documentary on Ramanujan. Indian legacy lives on.

**Srinivasa Ramanujan Iyengar** FRS (Fellow of Royal Society) was a legendary self-taught Indian mathematician and who, with almost *no formal training* in pure mathematics, made extraordinary contributions to mathematical analysis, number theory, infinite series, and continued fractions.

Ramanujan initially developed his own mathematical research in isolation; it was quickly recognized by Indian mathematicians. When his skills became apparent to the wider mathematical community, centred in Europe at the time, he began a famous partnership with the English mathematician G. H. Hardy. He rediscovered previously known theorems in addition to producing new theorems.

Ramanujan met deputy collector V. Ramaswamy Aiyer, who had recently founded the Indian Mathematical Society. Ramanujan, wishing for a job at the revenue department where Ramaswamy Aiyer worked, showed him his mathematics notebooks. As Ramaswamy Aiyer later recalled:

“I was struck by the extraordinary mathematical results contained in it [the notebooks]. I had no mind to smother his genius by an appointment in the lowest rungs of the revenue department.”

While still in Madras, Ramanujan recorded the bulk of his results in four notebooks of loose leaf paper. These results were mostly written up without any derivations. This is probably the origin of the misperception that Ramanujan was unable to prove his results and simply thought up the final result directly. Mathematician Bruce C. Berndt, in his review of these notebooks and Ramanujan’s work, says that Ramanujan most certainly was able to make the proofs of most of his results, but chose not to.

This style of working may have been for several reasons. Since paper was very expensive, Ramanujan would do most of his work and perhaps his proofs on slate, and then transfer just the results to paper. Using a slate was common for mathematics students in the Madras Presidency at the time. He was also quite likely to have been influenced by the style of G. S. Carr‘s book studied in his youth, which stated results without proofs. Finally, it is possible that Ramanujan considered his workings to be for his personal interest alone; and therefore recorded only the results.

The number** 1729** is known as the Hardy–Ramanujan number after a famous anecdote of the British mathematician G. H. Hardy regarding a visit to the hospital to see 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.’

The two different ways are

- 1729 = 1
^{3}+ 12^{3}= 9^{3}+ 10^{3}.

Generalizations of this idea have created the notion of “taxicab numbers“. Coincidentally, 1729 is also a Carmichael number.

Hardy said of Ramanujan: “He combined a power of generalization, a feeling for form, and a capacity for rapid modification of his hypotheses, that were often really startling, and made him, in his own peculiar field, without a rival in his day. The limitations of his knowledge were as startling as its profundity. Here was a man who could work out modular equations and theorems… to orders unheard of, whose mastery of continued fractions was… beyond that of any mathematician in the world, who had found for himself the functional equation of the zeta function and the dominant terms of many of the most famous problems in the analytic theory of numbers; and yet he had never heard of a doubly periodic function or of Cauchy’s theorem, and had indeed but the vaguest idea of what a function of a complex variable was…”

During his short life, Ramanujan independently compiled nearly 3,900 results (mostly identities and equations). Nearly all his claims have now been proven correct, although some were already known. He stated results that were both *original and highly unconventional*, such as the Ramanujan prime and the Ramanujan theta function, and these have inspired a vast amount of further research. The *Ramanujan Journal*, an international publication, was launched to publish work in all areas of mathematics influenced by his work.