A114932 Number of connected (3,n)-hypergraphs (without empty edges and without multiple edges).

0, 0, 1, 25, 267, 2265, 17471, 128765, 927067, 6591505, 46545591, 327428805, 2298406067, 16114352345, 112902172111, 790721005645, 5536667136267, 38763140938785, 271367842141031, 1899678231827285, 13298160713181667

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.

Formula

E.g.f.: (1/3!)*(exp(7*x)-3*exp(4*x)-exp(3*x)+3*exp(2*x)+2*exp(x)-2).

Mathematica

With[{nmax = 50}, CoefficientList[Series[(1/3!)*(Exp[7*x] - 3*Exp[4*x] - Exp[3*x] + 3*Exp[2*x] + 2*Exp[x] - 2), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)

Prog

(PARI) x='x+O('x^50); concat([0, 0], Vec(serlaplace((1/3!)*(exp(7*x)-3*exp(4*x)-exp(3*x)+3*exp(2*x)+2*exp(x)-2)))) \\ G. C. Greubel, Oct 07 2017

Crossrefs

Cf. A002501, A002502, A093732, A093733.

Cf. A114933, A114934, A114935, A114936, A114937.

Sequence in context: A221781 A298717 A058482 * A329537 A012859 A010830

Adjacent sequences: A114929 A114930 A114931 * A114933 A114934 A114935

Keyword

easy,nonn

Author

Goran Kilibarda and Vladeta Jovovic, Jan 08 2006

Status

approved