The lazy caterer's sequence, more formally known as the central polygonal numbers, describes the maximum number of pieces of a circle (a pancake or pizza is usually used to describe the situation) that can be made with a given number of straight cuts. For example, three cuts across a pancake will produce six pieces if the cuts all meet at a common point inside the circle, but up to seven if they do not. This problem can be formalized mathematically as one of counting the cells in an arrangement of lines; for generalizations to higher dimensions, see arrangement of hyperplanes. The analogue of this...

The Jantar Mantar is an equinoctial sundial, consisting a gigantic triangular gnomon with the hypotenuse parallel to the Earth's axis. On either side of the gnomon is a quadrant of a circle, parallel to the plane of the equator. The instrument is intended to measure the time of day, correct to half a second and declination of the Sun and the other heavenly bodies. There are five Jantar Mantar monuments in India, of which the largest is in Jaipur which features many instruments along with the world's largest stone sundial. The Vrihat Samrat yantra is a sundial that can give the local time to an...

Srinivasa Iyengar Ramanujan FRS (pronunciation: /ˈʃriːniˌvɑːsə ˈrɑːmɑːˌnʊdʒən/; 22 December 1887 – 26 April 1920) was an Indian mathematician and autodidact who lived during the British Raj. Though he had almost no formal training in pure mathematics, he made substantial 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 obvious and known to the wider mathematical community, centred in Europe at the time...