%I #6 Oct 15 2013 22:31:33

%S 2,1,2,4,4,7,6,8,9,11,10,12,12,15,16,16,16,18,18,20,22,23,22,24,25,27,

%T 27,28,28,29,30,32,34,35,36,36,36,39,40,40,40,41,42,44,45,47,46,48,49,

%U 50,52,52,52,54,56,56,58,59,58,60,60,63,63,64,66,65,66,68,70,69,70,72

%N n + mu(n), where mu is the Moebius-function (A008683).

%C a(n) = n iff n is not squarefree:

%C a(A013929(k))=A013929(k) and a(A005117(k))<>A005117(k).

%F a(n)=n+MoebiusMu[n]=A000027[n]+A008683[n].

%Y Cf. A000027, A008683, A063015, A076840.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_ and _Labos Elemer_, Oct 14 2002