A094037 Number of connected 6-element antichains on a labeled n-set.

0, 0, 0, 0, 1, 1345, 738741, 185165477, 29458046177, 3541242666045, 354515664467077, 31326419674855789, 2535191648955942273, 192567615994193565125, 13962461827318220986133, 978010022290154153870661

Offset

0,6

Links

Table of n, a(n) for n=0..15.

Formula

E.g.f.: (exp(63*x) - 30*exp(47*x) + 120*exp(39*x) + 60*exp(35*x) + 60*exp(33*x) - 18*exp(32*x) - 339*exp(31*x) - 720*exp(29*x) + 810*exp(27*x) + 120*exp(26*x) + 480*exp(25*x) + 480*exp(24*x) - 600*exp(23*x) - 720*exp(22*x) - 240*exp(21*x) - 900*exp(20*x) + 1740*exp(19*x) + 615*exp(18*x) + 180*exp(17*x) + 435*exp(16*x) - 1445*exp(15*x) - 3270*exp(14*x) + 1710*exp(13*x) + 4620*exp(12*x) - 3360*exp(11*x) - 3210*exp(10*x) + 3360*exp(9*x) + 6810*exp(8*x) - 12465*exp(7*x) + 5985*exp(6*x) + 7110*exp(5*x) - 18555*exp(4*x) + 17884*exp(3*x) - 8352*exp(2*x) + 1764*exp(x) - 120)/6!.

Crossrefs

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

Sequence in context: A270110 A224566 A053770 * A250088 A166193 A307586

Adjacent sequences: A094034 A094035 A094036 * A094038 A094039 A094040

Keyword

nonn

Author

Goran Kilibarda, Vladeta Jovovic, Apr 22 2004

Status

approved