
Glossary: Prime Pages: Top 5000: 
It seems natural (to some authors) to generalize the
notion of factorial primes by using the multifactorial
functions:
Since 7!!!!! can be hard to read (those of us getting older lose count of the !'s) and is easy to confuse with the huge number (((((7!)!)!)!)!, we will write 7!_{5} (i.e. using 5 as a subscript to the exclamation mark). More generally,
Ken Davis suggests that we also consider the forms n!!+ 2. Checking to n=5000 he has found: n!!2 is prime for n = 5, 7 , 15 , 17, 19, 51, 73, 89, 131, 153, 245, 333, 441, 463, 825, 1771, and 2027.
See Also: Factorial, FactorialPrime, PrimorialPrime Related pages (outside of this work) References:
Chris K. Caldwell © 19992016 (all rights reserved)
