A302048 - OEIS

%I #15 May 25 2019 16:05:02

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

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

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

%N a(n) = 1 if n = p^2 for some prime p, otherwise 0. Characteristic function of squares of primes (A001248).

%H Antti Karttunen, <a href="/A302048/b302048.txt">Table of n, a(n) for n = 0..66049</a>

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

%H <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a>

%F a(n) = A185012(A100995(n)) = A185012(A078898(n)) = A185012(A246277(n)).

%t Table[If[PrimeQ[Sqrt[n]],1,0],{n,0,130}] (* _Harvey P. Dale_, May 25 2019 *)

%o (PARI) A302048(n) = (2==isprimepower(n));

%Y Cf. A001248, A010051, A010052, A045698, A064911, A069513, A078898, A100995, A101040, A105700, A246277, A280710, A302047, A302049, A302777.

%K nonn

%O 0

%A _Antti Karttunen_, Apr 24 2018