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%I #11 Apr 25 2017 19:00:24
%S 1,2,2,3,2,5,3,2,6,7,2,3,10,11,5,2,6,13,14,6,15,3,2,17,6,7,19,10,21,
%T 22,2,23,6,5,26,3,14,29,30,31,10,2,33,34,35,6,11,37,38,39,10,41,6,42,
%U 43,22,15,2,46,3,13,47,6,7,10,51,26,14,53,6,55,5,14,57,58,15,59,30,61,62
%N Squarefree kernel of n-th perfect power.
%C a(n) = A007947(A001597(n)).
%H Reinhard Zumkeller, <a href="/A076403/b076403.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PerfectPower.html">Perfect Powers</a>.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SquarefreePart.html">Squarefree Part</a>.
%F a(n) = A007947(A025478(n)).
%t Prepend[Map[Times @@ FactorInteger[#][[All, 1]] &, DeleteCases[#, 0]], 1] &@ Table[If[Set[e, GCD @@ #[[All, -1]]] > 1, Power[n, 1/e], 0] &@ FactorInteger[n], {n, 4000}] (* _Michael De Vlieger_, Apr 25 2017 *)
%o (Haskell)
%o a076403 = a007947 . a025478 -- _Reinhard Zumkeller_, Mar 28 2014
%Y Cf. A025478.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Oct 09 2002