OFFSET
1,1
COMMENTS
The number of distinct-digit integers is finite therefore the sequence contains only zeros after n=31427. The last nonzero terms are a(31420)=492, a(31421)=414, a(31422)=378, a(31423)=648, a(31424)=382, a(31425)=338, a(31426)=720 and a(31427)=0, a(31428)=0...
EXAMPLE
a(10)=9 because between 10^2 and 11^2 there are 9 integers with distinct digits: 102, 103, 104, 105, 106, 107, 108, 109, 120.
MATHEMATICA
Table[Length[Select[Table[n, {n, x^2+1, (x+1)^2-1}], Length[IntegerDigits[ # ]]==Length[Union[IntegerDigits[ # ]]]&]], {x, 31428}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Sep 01 2002
STATUS
approved