OFFSET
1,1
COMMENTS
It is generally assumed that the Diophantine equation n! + 1 = m^2 can only be solved for n = 4,5,7. - Stefan Steinerberger, Aug 21 2007
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[1000], IntegerQ[Sqrt[Length[Divisors[ # ]]! + 1]] &] (* Stefan Steinerberger, Aug 21 2007 *)
Select[Range[200], IntegerQ[Sqrt[DivisorSigma[0, #]!+1]]&] (* Harvey P. Dale, Aug 04 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Aug 17 2007
EXTENSIONS
More terms from Stefan Steinerberger, Aug 21 2007
STATUS
approved