OFFSET
1,1
REFERENCES
Boris A. Kordemsky, The Moscow Puzzles (1972) at pp. 167, 295.
EXAMPLE
81368 = 8! + 1! + 3! + 6! + 8! + 1 = 40320 + 1 + 6 + 720 + 40320 + 1.
MATHEMATICA
fdQ[n_]:=Module[{c=Total[IntegerDigits[n]!]}, n==c+1||n==c-1]; Select[Range[400000], fdQ]
CROSSREFS
KEYWORD
nonn,fini,full,base
AUTHOR
Harvey P. Dale, Aug 24 2012
STATUS
approved