A354996 - OEIS

%I #12 Jun 18 2022 14:14:29

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,

%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,

%U 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1

%N a(n) = 1 if n > A034699(n)^2, otherwise 0, where A034699(n) is the largest prime power factor of n.

%H Antti Karttunen, <a href="/A354996/b354996.txt">Table of n, a(n) for n = 1..100000</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F a(n) = [A034699(n)^2 < n], where [ ] is the Iverson bracket.

%e For n = 30, A034699(30) = 5 and as 5^2 < 30, a(30) = 1.

%t a[n_] := If[n > Max[Power @@@ FactorInteger[n]]^2, 1, 0]; Array[a, 100] (* _Amiram Eldar_, Jun 18 2022 *)

%o (PARI)

%o A034699(n) = if(1==n, n, my(f=factor(n)); vecmax(vector(#f[, 1], i, f[i, 1]^f[i, 2])));

%o A354996(n) = (A034699(n)^2 < n);

%Y Characteristic function of A051283.

%Y Cf. A034699.

%K nonn

%O 1

%A _Antti Karttunen_, Jun 18 2022