A154664 Numbers n such that n!^2-+7493 are primes.

3, 4, 5, 6, 12

Offset

1,1

Comments

Next term is larger than 72

Next term is larger than 1000. - Harvey P. Dale, Feb 03 2016

Links

Table of n, a(n) for n=1..5.

Mathematica

lst={}; a=7493; Do[If[PrimeQ[n!^2-a]&&PrimeQ[n!^2+a], AppendTo[lst, n]], {n, 3*4!}]; lst
Select[Range[20], AllTrue[(#!)^2+{7493, -7493}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 03 2016 *)

Crossrefs

Cf. A144046, A154660, A154661, A154662, A154663

Sequence in context: A356050 A299299 A103402 * A371242 A366743 A191750

Adjacent sequences: A154661 A154662 A154663 * A154665 A154666 A154667

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jan 13 2009

Status

approved