login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A109581 E.g.f.: x/(1+x-x^3). 0

%I

%S 0,1,-2,6,0,-120,1440,-10080,40320,362880,-10886400,159667200,

%T -1437004800,0,348713164800,-9153720576000,146459529216000,

%U -1067062284288000,-25609494822912000,1338096104497152000,-34060628114472960000,510909421717094400000

%N E.g.f.: x/(1+x-x^3).

%H 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

%p 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

%t 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]

%Y Sequence having -G as o.g.f. is A104769.

%K sign

%O 0,3

%A _Roger L. Bagula_, Jun 29 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 15 08:46 EDT 2022. Contains 356135 sequences. (Running on oeis4.)