This is a very
useful site. You enter any positive integer and
it will return a prime factorization of that integer.
http://www.rsok.com/~jrm/factor.html
The Prime Pages; there is
a lot here. Articles include the "Guinness book
of" prime number records, how to find primes, conjectures
and open problems, and some special types of primes:
http://www.utm.edu/research/primes/
This is a nice
site, but is probably more than you want to know
about primes:
http://mathforum.org/library/topics/prime_numbers/
Listen to the
primes:
http://www.utm.edu/research/primes/programs/music/listen/
View the primes:
http://www.lactamme.polytechnique.fr/Mosaic/images/CONFORME.31.Fi.D/display.html
The largest
known primes:
http://www.utm.edu/research/primes/largest.html
A nice reference
for perfect numbers is at this site:
http://www-history.mcs.st-and.ac.uk/history/HistTopics/Perfect_numbers.html
There is a
lot of interesting material on the web concerning
Goldbach's conjecture. The follow site provides
a numerical calculator.
http://pass.maths.org.uk/issue2/xfile/
This is a fun
site that combines the ideas of divisibility and
patterns on Pascal's Triangle (which was introduced
in Chapter 1).
http://nlvm.usu.edu/en/nav/frames_asid_181_g_4_t_1.html
