A073444 Primes of the form n! - n - 1.

2, 19, 3628789, 479001587

Offset: 1

Author

Rick L. Shepherd, Jul 31 2002

Keywords

• nonn

Comments

a(5), a 730-digit number, has been certified prime with Primo.

Examples

			a(1) = 4! - 4 - 1 = 19, a prime, so 19 is in this sequence (4 = A073443(1)).
		

Crossrefs

Cf. A073443 (corresponding n).

Programs

PARI

for(n=3,2000, p=n!-n-1; if(isprime(p),print1(p,",")))

Formula

a(k) = A073443(k)! - A073443(k) - 1.