A084749 Numbers m such that m! + p is a prime, where p is the smallest prime > m.

0, 1, 2, 3, 4, 5, 6, 7, 10, 33, 44, 48, 52, 64, 73, 92, 119, 182, 487, 603, 987, 4884, 6822, 8070, 11079

Offset

1,3

Comments

Next term, if it exists, is >4800. - Ryan Propper, Jan 02 2007

From Farideh Firoozbakht, Oct 21 2009: (Start)

Numbers corresponding to a(19)-a(24) are probable primes.

There is no further term up to 8300. (End)

Links

Table of n, a(n) for n=1..25.

Example

727 = 6! + 7 is a prime but 8! + 11 is composite hence 6 is a member but 8 is not.
7 is in the sequence because 7!=5040, nextprime(7)=11 and 5040+11 is prime.

Mathematica

Do[If[PrimeQ[k!+NextPrime[k]], Print[k]], {k, 0, 1525}] (* Farideh Firoozbakht, Feb 26 2004 *)

Crossrefs

Cf. A084748, A084750, A092028, A064278, A002981, A151892.

Sequence in context: A230016 A306110 A092026 * A277883 A277196 A102453

Adjacent sequences: A084746 A084747 A084748 * A084750 A084751 A084752

Keyword

nonn,more

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 16 2003

Extensions

More terms from Farideh Firoozbakht, Feb 26 2004

Edited by N. J. A. Sloane at the suggestion of Artur Jasinski, Apr 14 2008

a(22)-a(24) from Farideh Firoozbakht, Oct 21 2009

a(25) from Michael S. Branicky, Aug 05 2024

Status

approved