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A326186 a(n) = n - A057521(n), where A057521 gives the powerful part of n.

%I A326186 #10 Nov 15 2022 02:37:23
%S A326186 0,1,2,0,4,5,6,0,0,9,10,8,12,13,14,0,16,9,18,16,20,21,22,16,0,25,0,24,
%T A326186 28,29,30,0,32,33,34,0,36,37,38,32,40,41,42,40,36,45,46,32,0,25,50,48,
%U A326186 52,27,54,48,56,57,58,56,60,61,54,0,64,65,66,64,68,69,70,0,72,73,50,72,76,77,78,64,0,81,82,80,84
%N A326186 a(n) = n - A057521(n), where A057521 gives the powerful part of n.
%H A326186 Antti Karttunen, <a href="/A326186/b326186.txt">Table of n, a(n) for n = 1..20000</a>
%F A326186 a(n) = n - A057521(n).
%o A326186 (PARI)
%o A326186 A057521(n) = { my(f=factor(n)); prod(i=1, #f~, if(f[i, 2]>1, f[i, 1]^f[i, 2], 1)); }; \\ From A057521.
%o A326186 A326186(n) = (n-A057521(n));
%o A326186 (Python)
%o A326186 from math import prod
%o A326186 from sympy import factorint
%o A326186 def A326186(n): return n-n//prod(p for p, e in factorint(n).items() if e == 1) # _Chai Wah Wu_, Nov 14 2022
%Y A326186 Cf. A057521, A326185.
%Y A326186 Cf. also A010848.
%K A326186 nonn
%O A326186 1,3
%A A326186 _Antti Karttunen_, Jul 11 2019