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A336644 a(n) = (n-rad(n)) / core(n), where rad(n) and core(n) give the squarefree kernel and squarefree part of n, respectively.

%I A336644 #13 Dec 30 2021 12:18:56
%S A336644 0,0,0,2,0,0,0,3,6,0,0,2,0,0,0,14,0,6,0,2,0,0,0,3,20,0,8,2,0,0,0,15,0,
%T A336644 0,0,30,0,0,0,3,0,0,0,2,6,0,0,14,42,20,0,2,0,8,0,3,0,0,0,2,0,0,6,62,0,
%U A336644 0,0,2,0,0,0,33,0,0,20,2,0,0,0,14,78,0,0,2,0,0,0,3,0,6,0,2,0,0,0,15,0,42,6,90,0,0,0,3,0
%N A336644 a(n) = (n-rad(n)) / core(n), where rad(n) and core(n) give the squarefree kernel and squarefree part of n, respectively.
%H A336644 Antti Karttunen, <a href="/A336644/b336644.txt">Table of n, a(n) for n = 1..16384</a>
%H A336644 Antti Karttunen, <a href="/A336644/a336644.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%F A336644 a(n) = A066503(n) / A007913(n) = (n-A007947(n)) / A007913(n).
%F A336644 a(n) = A008833(n) - A336643(n).
%o A336644 (PARI) A336644(n) = ((n-factorback(factorint(n)[, 1])) / core(n));
%o A336644 (Python)
%o A336644 from math import prod
%o A336644 from sympy.ntheory.factor_ import primefactors, core
%o A336644 def A336644(n): return (n-prod(primefactors(n)))//core(n) # _Chai Wah Wu_, Dec 30 2021
%Y A336644 Cf. A007913, A007947, A008833, A066503, A336642, A336643.
%K A336644 nonn
%O A336644 1,4
%A A336644 _Antti Karttunen_, Jul 28 2020