A052592 E.g.f. (1-x)/(1-4x).

1, 3, 24, 288, 4608, 92160, 2211840, 61931520, 1981808640, 71345111040, 2853804441600, 125567395430400, 6027234980659200, 313416218994278400, 17551308263679590400, 1053078495820775424000, 67397023732529627136000

Offset

0,2

Links

Table of n, a(n) for n=0..16.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 537

Formula

E.g.f.: (-1+x)/(-1+4*x).

Recurrence: {a(0)=1, a(1)=3, (-4-4*n)*a(n) + a(n+1)=0}.

a(n) = 3*4^(n-1)*n!, n>0.

Maple

spec := [S, {S=Sequence(Prod(Sequence(Z), Union(Z, Z, Z)))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);

Mathematica

s=3; lst={1, s}; Do[s+=n*s+s; AppendTo[lst, s], {n, 6, 5!, 4}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 08 2008 *)
With[{nn=20}, CoefficientList[Series[(1-x)/(1-4x), {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Nov 26 2011 *)

Prog

(PARI) Vec(serlaplace((-1+x)/(-1+4*x)+ O(x^30))) \\ Michel Marcus, Jan 09 2015

Crossrefs

Sequence in context: A064037 A257453 A128572 * A059381 A301933 A337027

Adjacent sequences: A052589 A052590 A052591 * A052593 A052594 A052595

Keyword

easy,nonn

Author

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

Status

approved