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).
Other numbers are visualized by means of colored spheres
(the luminance varies according to the number of divisors).
(CMAP28 WWW site: this page was created on 12/10/2001 and last updated on 04/26/2015
12:24:29 -CEST-)
