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A283336
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Expansion of exp( Sum_{n>=1} -sigma_6(n)*x^n/n ) in powers of x.
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6
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1, -1, -32, -211, -285, 5179, 44784, 162062, -125122, -5187417, -32587255, -95706881, 122837972, 3039216222, 17745876032, 52825817007, -24340390929, -1256623249600, -7805634068163, -26364952524572, -20649978457115, 368666542515083, 2777231006764690
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OFFSET
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0,3
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LINKS
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FORMULA
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G.f.: Product_{n>=1} (1 - x^n)^(n^5).
a(n) = -(1/n)*Sum_{k=1..n} sigma_6(k)*a(n-k).
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MATHEMATICA
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a[n_] := If[n<1, 1, -(1/n) * Sum[DivisorSigma[6, k] a[n - k], {k, n}]]; Table[a[n], {n, 0, 22}] (* Indranil Ghosh, Mar 16 2017 *)
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PROG
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(PARI) a(n) = if(n<1, 1, -(1/n) * sum(k=1, n, sigma(k, 6) * a(n - k)));
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CROSSREFS
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Cf. A023874 (exp( Sum_{n>=1} sigma_6(n)*x^n/n )).
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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