A154663 Numbers k such that k! + 767 and abs(k! - 767) are primes.

3, 5, 6, 7, 10, 11

Offset

1,1

Comments

Next term is larger than 240.

There are no more terms: none were found in a search past 767 and k! + 767 is divisible by 767 for all k >= 767. - Michael S. Branicky, May 18 2026

Links

Table of n, a(n) for n=1..6.

Mathematica

lst={}; a=767; Do[If[PrimeQ[n!-a]&&PrimeQ[n!+a], AppendTo[lst, n]], {n, 2*5!}]; lst
Select[Range[15], AllTrue[#!+{767, -767}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 13 2014 *)

Crossrefs

Cf. A144046, A154660, A154661, A154662.

Sequence in context: A379346 A055597 A053048 * A028983 A232682 A364289

Adjacent sequences: A154660 A154661 A154662 * A154664 A154665 A154666

Keyword

nonn,fini,full

Author

Vladimir Joseph Stephan Orlovsky, Jan 13 2009

Extensions

Definition corrected by Georg Fischer, May 18 2026

Status

approved