A125174 Primes of the form n! + (n+1)! - 1.

2, 7, 29, 839, 3991679, 93405311999, 1394852659199, 6758061133823999, 315777214062132212662271999999, 9146650338351415815045119999999, 303916116658416027343136804044799999999

Offset

1,1

Links

Table of n, a(n) for n=1..11.

Example

0!+1!-1 = 1 is not prime, 1!+2!-1 = 2 is prime, 2!+3!-1 = 7 is prime, 3!+4!-1 = 29 is prime, 4!+5!-1 = 143 = 11*13 is not prime.

Prog

(PARI) for(n=0, 35, if(isprime(a=n!+(n+1)!-1), print1(a, ", ")))

Crossrefs

Cf. A118913 (primes of the form n! + (n+1)! + 1).

Sequence in context: A359950 A094475 A093034 * A270526 A037417 A042913

Adjacent sequences: A125171 A125172 A125173 * A125175 A125176 A125177

Keyword

nonn

Author

Tomas Xordan, Jan 12 2007

Extensions

Edited and extended by Klaus Brockhaus, Jan 24 2007

Status

approved