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 A304820 A co-delta function for non-perfect powers. Dirichlet inverse of A304819. 3
 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 2, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,36 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = Sum_{d|n} A304779(d) * mu(n/d), where A304779 is the Dirichlet inverse of A304653. MATHEMATICA a[n_]:=a[n]=If[n==1, 1, -Sum[(-1)^PrimeOmega[d]*a[n/d], {d, Select[Rest[Divisors[n]], GCD@@FactorInteger[#][[All, 2]]==1&]}]]; Table[Sum[a[d]*MoebiusMu[n/d], {d, Divisors[n]}], {n, 100}] PROG (PARI) A304819(n) = sumdiv(n, d, if(!ispower(d), (-1)^bigomega(d), 0)); A304820(n) = if(1==n, 1, -sumdiv(n, d, if(d1)&&!ispower(d), ((-1)^bigomega(d))*A304779(n/d), 0))); A304820(n) = sumdiv(n, d, moebius(n/d)*A304779(d)); \\ Antti Karttunen, Jul 29 2018 CROSSREFS Positions of nonzero entries appear to be A126706. Cf. A000005, A000007, A001222, A001597, A005117, A007916, A008683, A008836, A304362, A304653, A304779, A304817, A304819. Sequence in context: A255320 A256574 A304819 * A162641 A333487 A185374 Adjacent sequences:  A304817 A304818 A304819 * A304821 A304822 A304823 KEYWORD nonn AUTHOR Gus Wiseman, May 19 2018 EXTENSIONS More terms from Antti Karttunen, Jul 29 2018 STATUS approved

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Last modified June 13 05:41 EDT 2021. Contains 344981 sequences. (Running on oeis4.)