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A052863 E.g.f.: log(-1/(-1+x))*exp(x) - log(-1/(-1+x)). 0
0, 0, 2, 6, 18, 65, 295, 1652, 11032, 85353, 749203, 7347384, 79564496, 942541041, 12121319327, 168145213732, 2502276609008, 39761200642225, 671855234838915, 12028625060491336, 227451564319791336 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Previous name was: A simple grammar.

LINKS

Table of n, a(n) for n=0..20.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 831

FORMULA

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

Recurrence: {a(1)=0, a(3)=6, a(2)=2, (-n^3-2*n-3*n^2)*a(n)+(19*n+11*n^2+2*n^3+10)*a(n+1)+(-38*n-12*n^2-n^3-36)*a(n+2)+(41+26*n+4*n^2)*a(n+3)+(-17-5*n)*a(n+4)+2*a(n+5), a(4)=18, a(5)=65}

a(n) = A002104(n)-(n-1)!. - Vladeta Jovovic, Apr 03 2005

a(n) ~ (n-1)! * (exp(1)-1). - Vaclav Kotesovec, Sep 29 2013

MAPLE

spec := [S, {B=Set(Z, 1 <= card), C=Cycle(Z), S=Prod(B, C)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);

MATHEMATICA

CoefficientList[Series[Log[-1/(-1+x)]*E^x-Log[-1/(-1+x)], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Sep 29 2013 *)

CROSSREFS

Sequence in context: A349367 A300335 A108066 * A037128 A150075 A150076

Adjacent sequences:  A052860 A052861 A052862 * A052864 A052865 A052866

KEYWORD

easy,nonn

AUTHOR

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

EXTENSIONS

New name using e.g.f., Joerg Arndt, Sep 30 2013

STATUS

approved

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Last modified November 26 21:07 EST 2021. Contains 349344 sequences. (Running on oeis4.)