Factorizations of Cunningham numbers with bases 13 to 99

This Report updates the tables of factorizations of an±1 for 13 ≤ a < 100, previously published asCWI Report NM-R9212 (June 1992) and updated in CWI Report NM-R9419 (Update 1, September1994) and CWI Report NM-R9609 (Update 2, March 1996). A total of 951 new entries in the tablesare given here. The factorizations are now complete for n < 76, and there are no composite cofactorssmaller than 10. This “Millennium edition” gives the complete tables incorporating all updates. A file containing onlythe new updates, a file containing factorizations for an extended table range, and a file of factors, areall available on the internet. 1991 Mathematics Subject Classification. Primary 11A25; Secondary 11-04