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a(n) = n - {the largest square that divides n}.
6

%I #11 Apr 21 2020 11:07:19

%S 0,1,2,0,4,5,6,4,0,9,10,8,12,13,14,0,16,9,18,16,20,21,22,20,0,25,18,

%T 24,28,29,30,16,32,33,34,0,36,37,38,36,40,41,42,40,36,45,46,32,0,25,

%U 50,48,52,45,54,52,56,57,58,56,60,61,54,0,64,65,66,64,68,69,70,36,72,73,50,72,76,77,78,64,0,81,82,80,84

%N a(n) = n - {the largest square that divides n}.

%H Antti Karttunen, <a href="/A326055/b326055.txt">Table of n, a(n) for n = 1..20000</a>

%F a(n) = n - A008833(n).

%F a(n) = A326054(n) + A033879(n).

%F a(A000203(n)) = A326040(n).

%t Table[n-Max[Select[Divisors[n],IntegerQ[Sqrt[#]]&]],{n,100}] (* _Harvey P. Dale_, Apr 21 2020 *)

%o (PARI)

%o A008833(n) = (n/core(n));

%o A326055(n) = (n-A008833(n));

%Y Cf. A000203, A000290, A008833, A033879, A326040, A326054, A326056.

%K nonn

%O 1,3

%A _Antti Karttunen_, Jun 05 2019