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 A088332 Primes of the form n! + 1. 18

%I

%S 2,3,7,39916801,10888869450418352160768000001,

%T 13763753091226345046315979581580902400000001,

%U 33452526613163807108170062053440751665152000000001

%N Primes of the form n! + 1.

%C Of course 2 = 0! + 1 = 1! + 1 has two such representations.

%C Prime numbers that are the sum of two factorial numbers. - _Juri-Stepan Gerasimov_, Nov 08 2010

%H T. D. Noe, <a href="/A088332/b088332.txt">Table of n, a(n) for n=1..11</a>

%H R. Mestrovic, <a href="http://arxiv.org/abs/1202.3670">Euclid's theorem on the infinitude of primes: a historical survey of its proofs (300 BC--2012) and another new proof</a>, arXiv preprint arXiv:1202.3670, 2012 - From N. J. A. Sloane, Jun 13 2012

%e 3! + 1 = 7 is prime.

%t lst={};Do[p=n!+1;If[PrimeQ[p],AppendTo[lst,p]],{n,0,3*5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jan 27 2009 *)

%o (PARI) factp1prime(n)=for(x=1,n,xf=x!+1; if(isprime(xf),print1(xf",")))

%Y Cf. A002981 (values of n).

%K nonn

%O 1,1

%A _Cino Hilliard_, Nov 06 2003

%E The next term is too large to include.

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Last modified May 29 15:44 EDT 2020. Contains 334704 sequences. (Running on oeis4.)