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A109581
E.g.f.: x/(1+x-x^3).
0
0, 1, -2, 6, 0, -120, 1440, -10080, 40320, 362880, -10886400, 159667200, -1437004800, 0, 348713164800, -9153720576000, 146459529216000, -1067062284288000, -25609494822912000, 1338096104497152000, -34060628114472960000, 510909421717094400000
OFFSET
0,3
FORMULA
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
MAPLE
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
MATHEMATICA
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]
CROSSREFS
Sequence having -G as o.g.f. is A104769.
Sequence in context: A213323 A293016 A122685 * A056876 A255484 A021797
KEYWORD
sign
AUTHOR
Roger L. Bagula, Jun 29 2005
STATUS
approved