cp's OEIS Frontend

A304339 Fixed point of f starting with n, where f(x) = x/(largest perfect power divisor of x).

%I A304339 #7 Aug 26 2018 18:08:32
%S A304339 1,2,3,1,5,6,7,1,1,10,11,3,13,14,15,1,17,2,19,5,21,22,23,3,1,26,1,7,
%T A304339 29,30,31,1,33,34,35,1,37,38,39,5,41,42,43,11,5,46,47,3,1,2,51,13,53,
%U A304339 2,55,7,57,58,59,15,61,62,7,1,65,66,67,17,69,70,71,2
%N A304339 Fixed point of f starting with n, where f(x) = x/(largest perfect power divisor of x).
%C A304339 All terms are squarefree numbers. First differs from A304328 at a(500) = 1, A304328(500) = 4.
%H A304339 Andrew Howroyd, <a href="/A304339/b304339.txt">Table of n, a(n) for n = 1..1000</a>
%e A304339 f maps 500 -> 4 -> 1 -> 1, so a(500) = 1.
%t A304339 radQ[n_]:=And[n>1,GCD@@FactorInteger[n][[All,2]]===1];
%t A304339 op[n_]:=n/Last[Select[Divisors[n],!radQ[#]&]];
%t A304339 Table[FixedPoint[op,n],{n,200}]
%o A304339 (PARI) a(n)={while(1, my(m=1); fordiv(n, d, if(ispower(d), m=max(m,d))); if(m==1, return(n)); n/=m)} \\ _Andrew Howroyd_, Aug 26 2018
%Y A304339 Cf. A000961, A001597, A001694, A005117, A007916, A052485, A052486, A059404, A091050, A160400, A203025, A294068, A303707, A304327, A304328.
%K A304339 nonn
%O A304339 1,2
%A A304339 _Gus Wiseman_, May 11 2018