| Aliquot: Sequences with initial term up to 10,000, by Christophe Clavier. |
| Aliquot Sequences: Juan L. Varona's work on aliquot sequences examines sequences with start values up to 10000, and traces them to large composite values. |
| Aliquot Sequences: Results and software from Paul Zimmermann, addressing the Catalan Conjecture and working on the difficult "Lehmer Five" sequences. |
| Aliquot Sequences: Aliquot sequences arise in iterating the sum-of-divisors function s. Bosma has calculated tables up to start value 50,000 and 80 digits. |
| Aliquot Sequences: Statistics by Wolfgang Creyaufmueller, including many tables and links to factoring sites and software. |
| Amicable Numbers: Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs. |
| Cubes of Perfection: From Ivars Peterson's MathTrek column in MAA Online. Curious relationships satisfied by perfect numbers. |
| Multiply Perfect Numbers: Up-to-date information on multiperfect numbers and searchable database maintained by Achim Flammenkamp. |
| Odd Perfect Numbers - Missing Values: Status of various factorisations that would extend the known area of non-existence of odd perfect numbers, by Kevin Hare. |
| On a Generalization of Perfect Numbers: 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. |
| Perfect Number - from MathWorld: Definitions and references. |
| Perfect Numbers: A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne discoveries. |
| Perfect Numbers: Harry J. Smith's pages of the mathematics behind perfect numbers, aliquot sequences and Mersenne numbers. Includes program listings and e-mail archives. |
| Tables of Aliquot Cycles: Data for various kinds up to 10^12, including unitary, infinitary, exponential, augmented and reduced varieties. |
| The Perfect Number Journey: A Mathematics Enrichment Workshop introducing perfect numbers. Lessons and exercises extend over several pages. Aimed at interested middle and high school students. |
Classical
