A093854 - OEIS

A093854

Triangle read by rows: T(n,m) = number of 3-uniform T_0-hypergraphs with n distinct edges and m vertices(n>=3, 1<=m<=2*n+1).

0, 0, 0, 4, 80, 480, 840, 0, 0, 0, 1, 200, 3840, 27720, 77280, 45360, 0, 0, 0, 0, 252, 14664, 263844, 2192400, 8709120, 13819680, 3991680, 0, 0, 0, 0, 210, 38340, 1518790, 26267360, 240765840, 1205492400, 3068881200, 3180038400, 605404800

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OFFSET

3,4

LINKS

Table of n, a(n) for n=3..42.

FORMULA

E.g.f.: (1+x)*exp(-x+x^2/2+x^3/3*y)*Sum((1+y)^binomial(n, 3)*exp(-x^2*(1+y)^n/2)*x^n/n!, n=0..infinity).

EXAMPLE

0,0,0,4,80,480,840; 0,0,0,1,200,3840,27720,77280,45360; 0,0,0,0,252,14664,263844,2192400,8709120,13819680,3991680; ...

CROSSREFS

Sequence in context: A204296 A192790 A211152 * A345459 A366955 A269146

Adjacent sequences: A093851 A093852 A093853 * A093855 A093856 A093857

KEYWORD

nonn,tabf

AUTHOR

Goran Kilibarda, Vladeta Jovovic, May 21 2004

STATUS

approved