Status of Search for Multifactorial Primes

For further information on� multifactorial primes please see Chris Caldwell's glossary page on Multifactorial Primes
This site continues the work of Ray Ballinger.

The MultiF project's, which started in 2003 aims to�

• �find all primes of the form n!k+/-1 where 2<=k<=25 up to one that is at least 100000 digits.

To participate

• email me, Ken Davis, at "kraDenken(at)yahoo(dot)com(dot)au" and reserve a type
• use multisieve to sieve a range of n (to eliminate those with small factors)
• use pfgw to find prps and prove primality
• Submit your prime to Chris Caldwell's The Prime Pages if big enough (Currently over 194000 digits)�
• Send me the Brillhart-Lehmer-Selfridge proof of primality output from pfgw
• I will add the (digits:nnnnn) and incorporate the data into the site

MultiF's position by number of Primes found
MultiF's position by score for Primes found

Discoverer Statistics

• 21/01/2012� Rene Dohmen proves 502051!7+1 (digits: 377722) prime (new multifactorial record)

• 18/01/2012 Nathan Russell provides stats on primality of number of the form n!10 +2

• 07/01/2012 Michael Lau proves 538508!23+1 (digits:124022), 544677!23+1 (digits:125560), 562746!23+1 (digits:130072) and 571312!23+1 (digits:132214) prime

• 19/09/2011 Rene Dohmen proves 478253!7+1� (digits: 358376)� prime (new multifactorial record)

• 21/07/2011 Matt Mills proves 257274!23-1 (digits: 55665) prime

• 06/06/2011 Rene Dohmen proves 446236!7-1� (digits: 332466)� prime (new multifactorial record)

• 27/05/2011 Nathan Russell uses Primo to certify 4213!6-2 prime

• 19/02/2011 Michael Lau proves 505855!23+1 (digits: 115904), 509171!23+1 (digits: 116727),� 509332!23+1� (digits : 116767), 514285!23+1� (digits: 117996) and� 521043!23+1� (digits: 119675) prime

• 26/01/2011 Rene Dohmen proves 368851!7-1 (digits: 270453)� prime (new multifactorial record)

• 18/12/2011 Rene Dohmen proves 364899!7+1 (digits: 267312) & 366923!7+1� (digits: 268920) prime (new multifactorial record)

Earlier news items

Recent changes are in Red

* Number of digits in the largest known prime of this form

Multifactorial primes of a different flavour n!k+/-2�