A177771 a(n) = (prime(n) - 1)!.

1, 2, 24, 720, 3628800, 479001600, 20922789888000, 6402373705728000, 1124000727777607680000, 304888344611713860501504000000, 265252859812191058636308480000000

Offset: 1

Author

Giovanni Teofilatto, May 13 2010

Keywords

• nonn

Comments

By Wilson's theorem, a(n) = -1 (mod p) where p is the n-th prime. - Charles R Greathouse IV, Sep 04 2013

References

• Paulo Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004. See p. 21.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..80

Crossrefs

Cf. A006093, A039716.

Programs

Magma

[Factorial(p-1): p in PrimesUpTo(20)]; // Vincenzo Librandi, May 31 2013

Mathematica

(Prime[Range[12]]-1)! (* Harvey P. Dale, Jul 12 2011 *)

PARI

apply(p->(p-1)!,primes(10)) \\ Charles R Greathouse IV, Sep 04 2013

Formula

a(n) = A010050(A005097(n-1)). a(n)^2 = A177926(n). - R. J. Mathar, May 24 2010