OFFSET
1,1
EXAMPLE
495918 is in the sequence because 4!+9!+5!+9!+1!+8! = 766225 and
495918766225 = 704215^2.
MATHEMATICA
sfdsQ[n_]:=Module[{f=Total[IntegerDigits[n]!]}, IntegerQ[ Sqrt[ n*10^IntegerLength[ f]+ f]]]; Select[Range[176*10^5], sfdsQ] (* Harvey P. Dale, Jul 06 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Jason Earls, Jun 16 2005
EXTENSIONS
Extended by Don Reble, Nov 21 2006
STATUS
approved