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 A354819 a(n) = 1 if n is a nonprime squarefree number, otherwise 0. 4
 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, 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, 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 LINKS Antti Karttunen, Table of n, a(n) for n = 1..100000 Index entries for characteristic functions Index entries for sequences computed from exponents in factorization of n FORMULA a(n) = A008966(n) * (1-A010051(n)). For all n >= 1, a(n) = a(A046523(n)). For all n > 1, a(n) <= A354353(n). MATHEMATICA a[n_] := If[!PrimeQ[n] && SquareFreeQ[n], 1, 0]; Array[a, 100] (* Amiram Eldar, Jun 11 2022 *) PROG (PARI) A354819(n) = ((1!=bigomega(n))&&issquarefree(n)); CROSSREFS Characteristic function of A000469. Cf. A008966, A010051, A046523, A322075, A354353, A354870 (inverse Möbius transform). Sequence in context: A339661 A374471 A320656 * A322075 A369255 A288220 Adjacent sequences: A354816 A354817 A354818 * A354820 A354821 A354822 KEYWORD nonn AUTHOR Antti Karttunen, Jun 10 2022 STATUS approved

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Last modified August 7 21:19 EDT 2024. Contains 375017 sequences. (Running on oeis4.)