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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A136868 Table read by antidiagonals: T(n,k) is the number of connected directed multigraphs with loops 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).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 2, 4, 1, 0, 1, 2, 6, 7, 1, 0, 1, 2, 6, 14, 12, 1, 0, 1, 2, 6, 17
Offset: 0

Views

Author

Benoit Jubin, May 11 2008

Keywords

Comments

Partial sums of the rows of A139624, i.e., T(n,k) = sum(T139624(n,p),p=0..k).
T(0,k) = 1 for k>=0; T(n,0) = 0 and T(n,1) = 1 for n>0.
If k>=n+1, T(n,k) = A139629(n).

Examples

			Triangle begins:
1,
1, 0,
1, 1, 0,
1, 2, 1, 0,
1, 2, 4, 1, 0,
1, 2, 6, 7, 1, 0,
1, 2, 6,14,12, 1, 0,
		

Crossrefs

Cf. A138352.