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!)
A052619 E.g.f. 3x^3/(1-x). 0
0, 0, 0, 18, 72, 360, 2160, 15120, 120960, 1088640, 10886400, 119750400, 1437004800, 18681062400, 261534873600, 3923023104000, 62768369664000, 1067062284288000, 19207121117184000, 364935301226496000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..19.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 564

FORMULA

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

Recurrence: {a(1)=0, a(0)=0, a(2)=0, (-1-n)*a(n)+a(n+1)=0, a(3)=18}

3*n!, n>2.

E.g.f. G(0)*3*x^3 where G(k)= 1 + x/(1 - x/( x + 1/G(k+1))); (continued fraction, 3rd kind, 3-step). - Sergei N. Gladkovskii, Jul 28 2012

MAPLE

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

CROSSREFS

Sequence in context: A069058 A262000 A007276 * A110753 A154670 A041626

Adjacent sequences:  A052616 A052617 A052618 * A052620 A052621 A052622

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 September 20 00:58 EDT 2021. Contains 347577 sequences. (Running on oeis4.)