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A139624 Table read by rows: T(n,k) is the number of connected directed multigraphs with loops and no vertex of degree 0, with n arcs and k vertices, which are transitive (the existence of a path between two points implies the existence of an arc between those two points). 4
1, 1, 1, 3, 2, 1, 6, 7, 3, 1, 11 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Length of the n^th row: n+1.

T(n,1) = 1

Row sums: A139629.

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

Triangle begins

1;

1, 1;

3, 2, 1;

6, 7, 3, 1;

CROSSREFS

Cf. A139623, A139625.

Sequence in context: A060408 A267121 A208518 * A132276 A257558 A202390

Adjacent sequences:  A139621 A139622 A139623 * A139625 A139626 A139627

KEYWORD

nonn,tabl

AUTHOR

Benoit Jubin, May 01 2008

STATUS

approved

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Last modified April 22 15:23 EDT 2021. Contains 343177 sequences. (Running on oeis4.)