%I #5 Jan 06 2019 15:37:23
%S 0,0,1,1,3,2,5,4,6,6,10,6,10,9,9,9,10,9,10,9,10,10,10,10,10,10,10,10,
%T 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
%U 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10
%N Number of distinct digits needed to write in decimal representation all positive non-divisors of n that are less than n.
%C a(n) = 10 for n > 20.
%e Set of non-divisors of n=12: {5,7,8,9,10,11}, therefore
%e a(12)=#{0,1,5,7,8,9}=6.
%t Table[Length[Union[Flatten[IntegerDigits/@Complement[Range[n],Divisors[ n]]]]],{n,80}] (* _Harvey P. Dale_, Jan 06 2019 *)
%Y Cf. A095048, A043537.
%K nonn,base
%O 1,5
%A _Reinhard Zumkeller_, May 28 2004