Web Directory

» Aliquot
   Sequences with initial term up to 10,000, by Christophe Clavier.
   http://christophe.clavier.free.fr/Aliquot/site/Aliquot.html

» Aliquot Sequences
   Statistics by Wolfgang Creyaufmueller, including many tables and links to factoring sites and software.
   http://www.aliquot.de/aliquote.htm

» Amicable Numbers
   Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs.
   http://www.shyamsundergupta.com/amicable.htm

» Cubes of Perfection
   From Ivars Peterson's MathTrek column in MAA Online. Curious relationships satisfied by perfect numbers.
   http://www.maa.org/mathland/mathtrek_5_18_98.html

» Multiply Perfect Numbers
   Up-to-date information on multiperfect numbers and searchable database maintained by Achim Flammenkamp.
   http://wwwhomes.uni-bielefeld.de/achim/mpn.html

» Perfect Number - from MathWorld
   Definitions and references.
   http://mathworld.wolfram.com/PerfectNumber.html

» Perfect Numbers
   A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne discoveries.
   http://www-history.mcs.st-and.ac.uk/history/HistTopics/Perfect_numbers.html

» Tables of Aliquot Cycles
   Data for various kinds up to 10^12, including unitary, infinitary, exponential, augmented and reduced varieties.
   http://amicable.homepage.dk/tables.htm