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A094729 Number of connected ordered 2-element multiantichains on a labeled n-set. 10
0, 1, 1, 7, 37, 151, 541, 1807, 5797, 18151, 55981, 171007, 519157, 1569751, 4733821, 14250607, 42850117, 128746951, 386634061, 1160688607, 3483638677, 10454061751, 31368476701, 94118013007, 282379204837, 847187946151 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..25.

FORMULA

E.g.f.: exp(3*x)-3*exp(2*x)+4*exp(x)-2.

Conjecture: a(n) = 4-3*2^n+3^n for n>0. a(n) = 6*a(n-1)-11*a(n-2)+6*a(n-3) for n>3. G.f.: -x*(12*x^2-5*x+1) / ((x-1)*(2*x-1)*(3*x-1)). - Colin Barker, Jul 07 2013

CROSSREFS

Cf. A094033-A094037, A094729-A094738.

Sequence in context: A012885 A162541 A196574 * A202659 A202119 A201083

Adjacent sequences:  A094726 A094727 A094728 * A094730 A094731 A094732

KEYWORD

nonn

AUTHOR

Goran Kilibarda, Vladeta Jovovic, May 24 2004

STATUS

approved

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Last modified July 25 10:20 EDT 2017. Contains 289792 sequences.