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a(n) = 1 if n is a nonprime squarefree number, otherwise 0.
4

%I #11 Jun 12 2022 15:16:35

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

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

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

%N a(n) = 1 if n is a nonprime squarefree number, otherwise 0.

%H Antti Karttunen, <a href="/A354819/b354819.txt">Table of n, a(n) for n = 1..100000</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) = A008966(n) * (1-A010051(n)).

%F For all n >= 1, a(n) = a(A046523(n)).

%F For all n > 1, a(n) <= A354353(n).

%t a[n_] := If[!PrimeQ[n] && SquareFreeQ[n], 1, 0]; Array[a, 100] (* _Amiram Eldar_, Jun 11 2022 *)

%o (PARI) A354819(n) = ((1!=bigomega(n))&&issquarefree(n));

%Y Characteristic function of A000469.

%Y Cf. A008966, A010051, A046523, A322075, A354353, A354870 (inverse Möbius transform).

%K nonn

%O 1

%A _Antti Karttunen_, Jun 10 2022