Prime Factorization of Cyclotomic Numbers
- Factor tables of cyclotomic numbers for values of phi(n) up to 120 by Mitsuo Morimoto.
- http://subsite.icu.ac.jp/people/mitsuo/enbunsu/intro-e.html

Factorizations of Repunit Numbers
- Tables available in text and compressed format.
- http://www.h4.dion.ne.jp/~rep/

Repunit Primes and Factors
- Factors of 10^n +- 1 for n<1000.
- http://www.swox.com/gmp/repunit.html

Factors of Numbers near Googolplex
- This table includes all known prime factors of the numbers in the range 10^(10^100) to 10^(10^100)+999, including more than 57000 prime factors of googolplex + 10.
- http://www.alpertron.com.ar/googol.htm

Factors of Modified Fermat Numbers
- Factors of numbers of the form 4^(3^n)+2^(3^n)+1 and 4^(3^n)-2^(3^n)+1.
- http://www.alpertron.com.ar/MODFERM.HTM

Brilliant Numbers
- Tables of maximal and minimal numbers with two, three or four prime factors of the same length (in decimal notation).
- http://www.alpertron.com.ar/BRILLIANT.HTM

Factors of 2^n + or - 1
- Factorizations for values of n up to 10000, extending the results of the Cunningham Project.
- http://www.euronet.nl/users/bota/medium-p.htm

Fermat Factoring Status
- Compiled by Wilfrid Keller, lists the known prime factors and complete factorizations of Fermat numbers.
- http://www.prothsearch.net/fermat.html

Factorization Results
- Tables, summaries, and links to many factoring endeavors, including primorials, factorials, and cyclotomic polynomials. Includes theorems and descriptions behind each project.
- http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/index.htm

Factor Tables
- Richard Brent's tables extend the scope of the Cunningham project (factoring b^n+-1) to all applicable bases b less than 100, plus some higher bases.
- http://web.comlab.ox.ac.uk/oucl/work/richard.brent/factors.html

Factorization of Cyclotomic Numbers
- Hisanori Mishima is coordinating the search and producing tables of factorizations of cyclotomic numbers for values of phi(n) less than 48.
- http://www.asahi-net.or.jp/~KC2H-MSM/cn/

Cunningham Project
- Current status of the project to factor numbers of the form b^n +/- 1, b = 2, 3, 5, 6, 7, 10, 11, and 12. Maintained by Samuel S. Wagstaff, jr.
- http://www.cerias.purdue.edu/homes/ssw/cun/