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 A329099 Expansion of 1 / (1 + Sum_{k>=1} mu(k)^2 * x^k). 0
 1, -1, 0, 0, 1, -2, 1, 0, 2, -4, 2, 0, 4, -10, 7, 0, 7, -23, 22, -6, 14, -51, 59, -24, 31, -113, 152, -80, 66, -244, 383, -253, 166, -521, 930, -746, 460, -1133, 2219, -2082, 1314, -2494, 5208, -5607, 3788, -5622, 12037, -14608, 10830, -13145, 27618, -37089, 30350, -31914, 63248, -92290 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS FORMULA G.f.: 1 / (1 + Sum_{k>=1} x^A005117(k)). MATHEMATICA nmax = 55; CoefficientList[Series[1/(1 + Sum[MoebiusMu[k]^2 x^k, {k, 1, nmax}]), {x, 0, nmax}], x] a[0] = 1; a[n_] := a[n] = -Sum[Boole[SquareFreeQ[k]] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 55}] CROSSREFS Cf. A002121, A005117, A008683, A280194. Sequence in context: A226075 A279226 A108354 * A329686 A261615 A146162 Adjacent sequences:  A329096 A329097 A329098 * A329100 A329101 A329102 KEYWORD sign AUTHOR Ilya Gutkovskiy, Nov 04 2019 STATUS approved

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Last modified September 24 12:23 EDT 2021. Contains 347642 sequences. (Running on oeis4.)