1,1

f[n_]:=n!-n; lst={}; Do[If[PrimeQ[f[n+1]-f[n]], AppendTo[lst, f[n+1]-f[n]]], {n, 0, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jun 27 2009]

For more terms see A049433.

Sequence in context: A128300 A001601 A061119 this_sequence A126579 A051710 A162713

Adjacent sequences: A049982 A049983 A049984 this_sequence A049986 A049987 A049988

nonn

N. J. A. Sloane (njas(AT)research.att.com).