A064401 Numbers n such that n! - prime(n) is prime.

4, 5, 7, 12, 14, 15, 16, 17, 18, 20, 30, 37, 39, 49, 52, 66, 86, 162, 165, 202, 235, 250, 366, 419, 1169, 1311, 1916, 3032, 3211, 3335, 4650, 6199, 7762

Offset

1,1

Comments

a(34) > 12500. - Giovanni Resta, Mar 16 2014

Links

Table of n, a(n) for n=1..33.

Mathematica

Do[ If[ PrimeQ[ n! - Prime[ n ] ], Print[ n ] ], {n, 1, 600} ]
Select[Range[2000], PrimeQ[#! - Prime[#]] &] (* Vincenzo Librandi, Mar 05 2015 *)

Prog

(Magma) [n: n in [1..200] | IsPrime(Factorial(n)- NthPrime(n))]; // Vincenzo Librandi, Mar 05 2015

Crossrefs

Cf. A064278.

Sequence in context: A216536 A051658 A047491 * A079337 A160934 A032390

Adjacent sequences: A064398 A064399 A064400 * A064402 A064403 A064404

Keyword

nonn,more,hard

Author

Robert G. Wilson v, Sep 28 2001

Extensions

Three more terms from Farideh Firoozbakht, Feb 28 2004

a(28)-a(33) from Giovanni Resta, Mar 16 2014

Status

approved