OFFSET
1,1
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Smith Number
Wikipedia, Smith number
MATHEMATICA
d[n_]:=IntegerDigits[n]; dr[n_]:= NestWhile[Total[d[#]]&, n, #>9&]; tr[n_]:=Transpose[FactorInteger[n]]; t1=Select[Range[4, 2.2*10^3], !PrimeQ[#]&&Total[d[#]]==Total[d@tr[#][[1]]*tr[#][[2]], 2]&]; Table[dr[n], {n, t1}] (* t1 gives Smith numbers - Jayanta Basu, Jun 04 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Dec 19 2011
STATUS
approved