A151894 Numbers n such that n! + second prime after n! is prime.

2, 3, 5, 6, 7, 8, 11, 17, 42, 66, 76, 93, 139, 157

Offset

1,1

Comments

Because numbers of the form: (n! + prime) are divisible by all primes <= n that mean that first prime number can have form n! + next prime after n! and no primes of the form n! + k for k > 1 and k < next prime after n!

Links

Table of n, a(n) for n=1..14.

Mathematica

a = {}; Do[If[PrimeQ[n! + NextPrime[n!, 2]], AppendTo[a, n]], {n, 1, 200]; a (*Artur Jasinski*)

Crossrefs

Cf. A002981, A151892, A151893, A151903.

Sequence in context: A191167 A006431 A285528 * A352328 A028229 A104452

Adjacent sequences: A151891 A151892 A151893 * A151895 A151896 A151897

Keyword

nonn

Author

Artur Jasinski, Apr 12 2008

Status

approved