A175194 a(n) = the smallest factorial such that (the n-th prime)+a(n) is prime, or -1 if no such prime exists.

1, 2, 2, 6, 2, 6, 2, 24, 6, 2, 6, 6, 2, 24, 6, 6, 2, 6, 6, 2, 6, 24, 6, 24, 6, 2, 6, 2, 120, 24, 24, 6, 2, 24, 2, 6, 6, 120, 6, 6, 2, 362880, 2, 6, 2, 24, 120, 6, 2, 120, 6, 2, 5040, 6, 6, 6, 2, 6, 6, 2, 24, 24, 6, 2, 24, 40320, 6, 120, 2, 24, 6, 24, 6, 6, 120, 6, 120, 24, 120, 24, 2, 120, 2

Offset: 1

Author

Leroy Quet, Mar 01 2010

Keywords

• nonn

Comments

a(n) = A175193(n)!.

Crossrefs

Cf. A082470, A092789, A175193.

Formula

A092789(n) = A000040(n) + a(n).

Extensions

Extended by Ray Chandler, Mar 04 2010