OFFSET
1,1
COMMENTS
EXAMPLE
203 because 203 = 7 * 29, which have 1 and 2 digits, respectively.
MATHEMATICA
Take[Union[Times@@@Select[Subsets[Prime[Range[50]], {2}], IntegerLength[#[[1]]]!=IntegerLength[#[[2]]]&]], 60] (* Harvey P. Dale, Dec 29 2010 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jul 15 1998
STATUS
approved