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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
OFFSET
1,4
COMMENTS
Length of the n-th row: n+1.
T(n,1) = 1
Row sums: A139629.
EXAMPLE
Triangle begins
1;
1, 1;
3, 2, 1;
6, 7, 3, 1;
CROSSREFS
Sequence in context: A060408 A267121 A208518 * A132276 A257558 A370470
KEYWORD
nonn,tabl,more
AUTHOR
Benoit Jubin, May 01 2008
STATUS
approved