A094036 Number of connected 5-element antichains on a labeled n-set.

0, 0, 0, 0, 6, 2005, 280971, 22795136, 1345702092, 65250058251, 2781911443317, 108660434574142, 3991349973006198, 140293749275697017, 4775521611056597583, 158758002632650598268, 5185922974307536588224

Offset

0,5

Links

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

Formula

E.g.f.: (exp(31*x)-20*exp(23*x)+60*exp(19*x)+20*exp(17*x)

+5*exp(16*x)-105*exp(15*x)-120*exp(14*x)+150*exp(13*x)+180*exp(12*x)

-300*exp(11*x)-110*exp(10*x)+380*exp(9*x)+160*exp(8*x)-575*exp(7*x)

+570*exp(6*x)-186*exp(5*x)-975*exp(4*x)+1645*exp(3*x)-1030*exp(2*x)

+274*exp(x)-24)/5!.

Crossrefs

Cf. A016269, A047707, A051112-A051118, A094033-A094037.

Sequence in context: A209496 A341872 A024086 * A053293 A209737 A209458

Adjacent sequences: A094033 A094034 A094035 * A094037 A094038 A094039

Keyword

nonn

Author

Goran Kilibarda, Vladeta Jovovic, Apr 22 2004

Status

approved