A189898 - cp's OEIS frontend

A189898 Triangular array read by rows. T(n,k) is the number of digraphs with n labeled nodes having exactly k undirected (or weak) components, n >= 1, 1 <= k <= n.

n	a(n)
1	1
2	3
3	1
4	54
5	9
6	1
7	3834
8	243
9	18
10	1
11	1027080
12	20790
13	675
14	30
15	1
16	1067308488
17	6364170
18	67635
19	1485
20	45
21	1
22	4390480193904
23	7543111716
24	23031540
25	171045
26	2835
27	63
28	1
29	72022346388181584
30	35217115838604
31	30469951764
32	63580545
33	370440
34	4914
35	84
36	1

[1, 3, 1, 54, 9, 1, 3834, 243, 18, 1, 1027080, 20790, 675, 30, 1, 1067308488, 6364170, 67635, 1485, 45, 1, 4390480193904, 7543111716, 23031540, 171045, 2835, 63, 1, 72022346388181584, 35217115838604, 30469951764, 63580545, 370440, 4914, 84, 1]

cp's OEIS Frontend

A189898 Triangular array read by rows. T(n,k) is the number of digraphs with n labeled nodes having exactly k undirected (or weak) components, n >= 1, 1 <= k <= n.

Table of values

List of values