

A055490


Factorial primes: primes of the form n!  1.


11




OFFSET

1,1


COMMENTS

For further information see A002982, which is the main entry.
Also primes of the form (n!1) mod (n1)!, with n>=1.  Paolo P. Lava & Giorgio Balzarotti, Mar 14 2007. [This follows because every number of the form (n!1) mod (n1)! is 1 less than a factorial.]
Also primes of the form 1*1! + 2*2! + ... + n*n!. Example: 1*1! + 2*2! + 3*3! + 4*4! + 5*5! + 6*6! + 7*7! + 8*8! + 9*9! + 10*10! + 11*11! + 12*12! + 13*13! = 87178291199 is prime.  Jonathan Vos Post, Jul 21 2006
Prime numbers that are the difference of two factorial numbers.  JuriStepan Gerasimov, Nov 08 2010


LINKS

T. D. Noe, Table of n, a(n) for n=1..12


FORMULA

p = n!1 for some n given in A002982.


MATHEMATICA

lst={}; Do[p=n!1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 5*5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 27 2009 *)
Select[Range[40]!1, PrimeQ] (* Harvey P. Dale, Aug 16 2012 *)


CROSSREFS

Cf. A000142, A000203, A002982.
Sequence in context: A080990 A172036 A003487 * A261935 A299360 A002811
Adjacent sequences: A055487 A055488 A055489 * A055491 A055492 A055493


KEYWORD

nonn


AUTHOR

Labos Elemer, Jun 28 2000


EXTENSIONS

Edited by Jon E. Schoenfield, Jan 09 2015


STATUS

approved



