OFFSET
1,1
COMMENTS
MATHEMATICA
FromDigits/@(Flatten[Permutations/@Table[Join[Table[1, {n}], Table[9, {n}]], {n, 4}], 1]) (* Harvey P. Dale, Aug 20 2014 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Jonathan Vos Post, Jul 20 2012
STATUS
approved