A093622 Largest prime of the form n!/k!-1.

5, 23, 59, 719, 5039, 6719, 181439, 5039, 6652799, 479001599, 154439, 87178291199, 54486431999, 3487131647999, 59281238015999, 1067062284287999, 1013709170073599, 405483668029439999, 39070079, 180503769599

Offset: 3

Author

Hugo Pfoertner, Apr 06 2004

Keywords

• nonn

Examples

			a(5) =59 because 5!/1!-1=119=7*17 is composite, whereas 5!/2!-1=59 is prime.
		

Links

• Dario Alpern, Factorization using the Elliptic Curve Method.

Crossrefs

Cf. A093623 smallest k>0 such that n!/k!-1 is prime, A055490 primes of form n!-1, A093437 largest prime of the form n!/k!+1.