Starting from the lower left point, the spheres are
numbered (1, 2, 3,...) on successive lines
in order to build the Eratosthene sieve. The radius of the N-th sphere is proportional
to the square root of the number of divisors of N.
The number 1 and the prime numbers are visualized by means of white spheres
(a smaller one for the number 1).
(CMAP28 WWW site: this page was created on 02/05/1999 and last updated on 04/26/2015
12:24:24 -CEST-)
