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).

1, 1, 1, 3, 2, 1, 6, 7, 3, 1, 11

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,more

Author

Benoit Jubin, May 01 2008

Status

approved