Factors (Popularity: )

Lists the factors of every single number up to 600, for quick reference and as ...

Factors of Modified Fermat Numbers (Popularity: )

Factors of numbers of the form 4^(3^n)+2^(3^n)+1 and 4^(3^n)-2^(3^n)+1.

Divisibility Criteria (Popularity: )

Ways of telling whether one number divides another without actually carrying the division through, constructed ...

The Perfect Number Journey (Popularity: )

A Mathematics Enrichment Workshop introducing perfect numbers. Lessons and exercises extend over several pages. Aimed ...

Amicable Numbers (Popularity: )

Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs.

Repunit Primes and Factors (Popularity: )

Factors of 10^n +- 1 for n<1000.

Factoring Papers (Popularity: )

Links to papers on the theory and practice of factoring.

Fermat Factoring Status (Popularity: )

Compiled by Wilfrid Keller, lists the known prime factors and complete factorizations of Fermat numbers.

Digital Divisibility Tests (Popularity: )

From Carlos Rivera's Prime Puzzles and Problems collection. Carlos asks for the general divisibility rules ...

Integer Factorization (Popularity: )

Paul Leyland's list of his own and other factorisations.

Aliquot (Popularity: )

Sequences with initial term up to 10,000, by Christophe Clavier.

Factorizations of Repunit Numbers (Popularity: )

Tables available in text and compressed format.

Perfect Numbers (Popularity: )

A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne ...

Aliquot Sequences (Popularity: )

Juan L. Varona's work on aliquot sequences examines sequences with start values up to 10000, ...

Cunningham Project (Popularity: )

Current status of the project to factor numbers of the form b^n +/- 1, b ...

Computing Aurifeuillian factors (Popularity: )

Algorithm that finds non-trivial factors of certain numbers of the form a^b +/- 1.

Discovery of a Lost Factoring Machine (Popularity: )

Built by a French amateur, E.-O. Carissan, around 1919. Shallit, Williams and Morain include photographs ...

Divisibility Tests (Popularity: )

From the Furman University Electronic Journal of Undergraduate Mathematics. Apoorva Khare's paper is available as ...

Factor Tables (Popularity: )

Richard Brent's tables extend the scope of the Cunningham project (factoring b^n+-1) to all applicable ...

Factoring Fermat Numbers (Popularity: )

Cash prizes for new factors of Fermat numbers Fn, for n = 12 through 22.