Regular number

From Wikipedia, the free encyclopedia

In the study of Babylonian mathematics, a regular number is a whole number which divides a power of 60. In the Babylonian sexagesimal notation, this means that the reciprocal of the number has a finite representation, thus being easy to divide by; and tables of such reciprocals survive.

John Horton Conway and Richard Guy interpret the broken cuneiform tablet Plimpton 322 as being the Pythagorean triples $( p^2 - q^2,\, 2pq,\, p^2 + q^2 )$ generated by p, q both regular and less than 60.