%I A071540
%S A071540 4,57,664,7068,73130,747244,7590269
%N A071540 Number of k's less than or equal to 10^n such that there are no middle 
               divisors of k (A071090).
%t A071540 f[n_] := Plus @@ Select[ Divisors[n], Sqrt[n/2] <= # < Sqrt[n*2] &]; 
               s = 0; k = 0; Do[ While[k < 10^n, k++; If[ f[k] == 0, s++ ]]; Print[s], 
               {n, 1, 7}]
%Y A071540 Cf. A071541.
%Y A071540 Sequence in context: A060497 A092273 A156873 this_sequence A103907 A108148 
               A099348
%Y A071540 Adjacent sequences: A071537 A071538 A071539 this_sequence A071541 A071542 
               A071543
%K A071540 nonn
%O A071540 1,1
%A A071540 Robert G. Wilson v (rgwv(AT)rgwv.com), May 31 2002