A109582 Expansion of e.g.f.: -1/(1+x-x^3).

-1, 1, -2, 0, 24, -240, 1440, -5040, -40320, 1088640, -14515200, 119750400, 0, -24908083200, 610248038400, -9153720576000, 62768369664000, 1422749712384000, -70426110763008000, 1703031405723648000, -24329020081766400000, -51090942171709440000

Offset: 0

Author

Roger L. Bagula, Jun 29 2005

Keywords

• sign

Crossrefs

Cf. A050935, A104769.

Programs

Maple

g:=-1/(1+x-x^3):gser:=series(g,x=0,26): -1,seq(n!*coeff(gser,x^n),n=1..22);

Formula

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

a(n) = n!*A104769(n+1). - R. J. Mathar, Aug 20 2021

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