This page is a summary of the Multifactorial search status as of 25 July 2001 (All data is reflected into the current site).  

Status of Search for Multifactorial Primes

For information about multifactorial primes please see Chris Caldwell's glossary page on Multifactorial Primes and his list of the top 20 Primorial and Factorial Primes.

Ken Davis has kindly agreed to keep up this page at his Multifactorial Prime Page. New data will be updated only on his site.

Multifactorials are of the form forms n!!+/-1, n!!!+/-1, n!!!!+/-1 ...
We shall call these 2-factorial plus or minus one, 3-factorial plus or minus one and so on.

nmax tested Current searcher
n!-1 (10000) 10900 Bouk de Water
n!!+1 16000  
n!!-1 12500 Bouk de Water
n!!!+1 32600 Steven Harvey/Dan Routman
n!!!-1 34400 Steven Harvey
n!!!!+1 25000 Bruce Ziemienski
n!!!!-1 30300 Free
n!5+1 7000  Bouk de Water
n!5-1 13300 Bouk de Water
n!6+1 33000 Ray Ballinger
n!6-1 55500 Ray Ballinger
n!7+1   Iago L Camboa
n!7-1 39500 Rene Dohmen
n!8+1 12700 Marc Thibeault
n!8-1 7000 Marc Thibeault
n!9+1 11000 Bouk de Water
n!9-1 11000 Bouk de Water
n!10+1 48700 Steve Harvey
n!10-1 13000 Michael
n!11+1 31000 Michael Bell/Ray Ballinger
n!11-1 29500 Free
n!12+1 17200 Dirk Augustin
n!12-1 14000 Dirk Augustin
n!13+1 17000 Dirk Augustin
n!13-1 12500 Dirk Augustin
n!14+1 6000 Free
n!14-1 6000 Free
n!17+1 40000 Michael Bell
n!17-1 25000 Michael Bell
n!20+1 20000 Micha Fleuren
n!20-1 15400 Micha Fleuren
n!21+1 8500 Micha Fleuren
n!21-1 8500 Micha Fleuren
n!22+1 17300 Micha Fleuren
n!22-1 17300 Micha Fleuren
n!23+1 20000 Michael Lau
n!24+1 20000 Didier BOIVIN
n!100+-1   Hans Rosenthal
n!101+-1   Hans Rosenthal

To test for multifactorial primes, you may use primeform 

Last Modified: 25 July 2001
Address questions about this web page to: Ray Ballinger