A general formula by which these numbers could be derived was invented by the Arabian astronomer Tobit ben Korra (836-901): if p = 3.2 m - I, q= 3.2 m - 1 - 1 and r = 9.2 2m - 1 - I, where m is an integer and p,q,r prime numbers, then 2 m pq and 2 m r are a pair of amicable numbers.
1007), Rene Descartes, to whom the formula of Tobit ben Korra is sometimes ascribed, C. Rudolphus and others.
But these translations were regarded as imperfect, and it remained for Tobit ben Korra (836-901) to produce a satisfactory edition.
Tobit ben Korra (836-901), born at Harran in Mesopotamia, an accomplished linguist, mathematician and astronomer, rendered conspicuous service by his translations of various Greek authors.
These problems were also attacked by the Arabian mathematicians; Tobit ben Korra (836-901) is credited with a solution, while Abul Gud solved it by means of a parabola and an equilateral hyperbola.
By Tobit ben Korra (836-901).
Korra(30s), a game of skill for a long time in great vogue at ancient Greek drinking parties, especially in the 4th and sth centuries B.C. It is frequently alluded to by the classical writers of the period, and not seldom depicted on ancient vases.
(I) In the Korra/30s Si òu43 t4 cw shallow saucers (4143a4a) were floated in a basin or mixing-bowl filled with water; the object was to sink the saucers by throwing the wine into them, and the competitor who sank the greatest number was considered victorious, and received the prize, which consisted of cakes or sweetmeats.
(2) Korra(30s KaTaKTOs, 1 is not so easy to understand, although there is little doubt as to the apparatus.