A136868 - cp's OEIS frontend

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).

n	a(n)
0	1
1	1
2	0
3	1
4	1
5	0
6	1
7	2
8	1
9	0
10	1
11	2
12	4
13	1
14	0
15	1
16	2
17	6
18	7
19	1
20	0
21	1
22	2
23	6
24	14
25	12
26	1
27	0
28	1
29	2
30	6
31	17

[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]