A307240 a(0) = 1; a(n) = Sum_{k=1..n} -lambda(k+1)*a(n-k), where lambda() is the Liouville function (A008836).
1, 1, 2, 2, 4, 4, 8, 10, 18, 22, 38, 50, 84, 114, 186, 256, 406, 570, 896, 1280, 1986, 2862, 4394, 6380, 9730, 14224, 21582, 31690, 47872, 70544, 106248, 157016, 235930, 349382, 523976, 777144, 1163882, 1728396, 2585802, 3843568, 5745510, 8546218, 12767232, 19001168
Offset: 0
Keywords
Programs
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Mathematica
a[0] = 1; a[n_] := a[n] = Sum[-LiouvilleLambda[k + 1] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 43}] nmax = 43; CoefficientList[Series[x/Sum[LiouvilleLambda[k] x^k, {k, 1, nmax + 1}], {x, 0, nmax}], x]
Formula
G.f.: x / Sum_{k>=1} lambda(k)*x^k.