login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A052671 E.g.f. x^3*(1-x)/(1-2x). 0
0, 0, 0, 6, 24, 240, 2880, 40320, 645120, 11612160, 232243200, 5109350400, 122624409600, 3188234649600, 89270570188800, 2678117105664000, 85699747381248000, 2913791410962432000, 104896490794647552000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..18.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 619

FORMULA

E.g.f.: x^3*(-1+x)/(-1+2*x)

Recurrence: {a(1)=0, a(0)=0, a(2)=0, a(3)=6, (-2*n-2)*a(n)+a(n+1)=0, a(4)=24}

2^(n-4)*n!, n>3.

MAPLE

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

MATHEMATICA

With[{nn=20}, CoefficientList[Series[x^3(-1+x)/(-1+2x), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Nov 13 2014 *)

CROSSREFS

Sequence in context: A223105 A112675 A052583 * A052733 A323449 A010567

Adjacent sequences:  A052668 A052669 A052670 * A052672 A052673 A052674

KEYWORD

easy,nonn

AUTHOR

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

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 8 05:33 EDT 2020. Contains 335513 sequences. (Running on oeis4.)