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A109581
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E.g.f.: x/(1+x-x^3).
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0
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0, 1, -2, 6, 0, -120, 1440, -10080, 40320, 362880, -10886400, 159667200, -1437004800, 0, 348713164800, -9153720576000, 146459529216000, -1067062284288000, -25609494822912000, 1338096104497152000, -34060628114472960000, 510909421717094400000
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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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D-finite with recurrence a(n) + n*a(n-1) - n*(n-1)*(n-2)*a(n-3) = 0. - R. J. Mathar, Aug 20 2021
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MAPLE
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G:=x/(1+x-x^3): Gser:=series(G, x=0, 26): 0, seq(n!*coeff(Gser, x^n), n=1..23); # yields signed sequence
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MATHEMATICA
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g[x_] = x/(-1 - x + x^3) h[x_, n_] = Dt[g[x], {x, n}] a[x_] = Table[h[x, n], {n, 0, 25}]; b = a[0]
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CROSSREFS
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Sequence having -G as o.g.f. is A104769.
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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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