cp's OEIS Frontend

A132349 If n is a k-th power with k >= 2 then a(n) = k, otherwise a(n) = 0.

%I A132349 #10 Aug 13 2024 05:33:40
%S A132349 0,0,0,2,0,0,0,3,2,0,0,0,0,0,0,4,0,0,0,0,0,0,0,0,2,0,3,0,0,0,0,5,0,0,
%T A132349 0,2,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,6,0,0,0,0,
%U A132349 0,0,0,0,0,0,0,0,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2
%N A132349 If n is a k-th power with k >= 2 then a(n) = k, otherwise a(n) = 0.
%H A132349 Antti Karttunen, <a href="/A132349/b132349.txt">Table of n, a(n) for n = 1..10000</a>
%t A132349 a[n_] := Boole[(g = GCD @@ FactorInteger[n][[;;,2]]) > 1] * g; Array[a, 100] (* _Amiram Eldar_, Aug 13 2024 *)
%o A132349 (PARI) r(n) = for(j=1,n,print1(ispower(j)","));
%o A132349 r(100)
%Y A132349 Cf. A132350, A132351, A132352, A132384.
%K A132349 nonn
%O A132349 1,4
%A A132349 _N. J. A. Sloane_, Nov 11 2007