
Re: cotpi 67  Composite factorial plus one
Posted:
Mar 8, 2013 2:55 AM


On Mar 8, 12:13 am, m...@vex.net (Mark Brader) wrote: > > How many positive integers n are there such that n! + 1 is > > composite? > > Infinitely many, or to be more specific, alephnull. > > Wilson's theorem states that if p is prime, then (p1)! + 1 is > divisible by p. If x > 3, then (x1)! + 1 > x. Therefore the > desired property holds for all numbers n > 4 where n1 is prime, > and there are alephnull of those.
Fine, but I think you mean n+1 is prime, not n1.

