Perfect Numbers
www-history.mcs.st-and.ac.uk
A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne discoveries.
Aliquot
christophe.clavier.free.fr
Sequences with initial term up to 10,000, by Christophe Clavier.
Aliquot Sequences
loria.fr
Results and software from Paul Zimmermann, addressing the Catalan Conjecture and working on the difficult "Lehmer Five" sequences.
Cubes of Perfection
maa.org
From Ivars Peterson's MathTrek column in MAA Online. Curious relationships satisfied by perfect numbers.
Aliquot Sequences
unirioja.es
Juan L. Varona's work on aliquot sequences examines sequences with start values up to 10000, and traces them to large composite values.
Tables of Aliquot Cycles
amicable.homepage.dk
Data for various kinds up to 10^12, including unitary, infinitary, exponential, augmented and reduced varieties.
Aliquot Sequences
math.ru.nl
Aliquot sequences arise in iterating the sum-of-divisors function s. Bosma has calculated tables up to start value 50,000 and 80 digits.
Perfect Number - from MathWorld
mathworld.wolfram.com
Definitions and references.
On a Generalization of Perfect Numbers
geocities.com
J. L. Pe introduces perfect numbers relative to an arithmetical function f. Under this scheme, the usual perfect numbers are just one among many species of "f-perfect numbers". Several open problems and examples of perfect number sets are given, as well as a few f-amicable pairs.
Multiply Perfect Numbers
wwwhomes.uni-bielefeld.de
Up-to-date information on multiperfect numbers and searchable database maintained by Achim Flammenkamp.
Amicable Numbers
shyamsundergupta.com
Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs.
- Perfect Numbers
geocities.com
Harry J. Smith's pages of the mathematics behind perfect numbers, aliquot sequences and Mersenne numbers. Includes program listings and e-mail archives.
Aliquot Sequences
aliquot.de
Statistics by Wolfgang Creyaufmueller, including many tables and links to factoring sites and software.
