A368569 - cp's OEIS frontend

A368569 Irregular triangle read by rows: T(n,k) is the number of essential graphs with n nodes and k (directed or undirected) edges (n >= 1, 0 <= k <= n*(n-1)/2).

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	6
7	1
8	1
9	6
10	27
11	60
12	66
13	24
14	1
15	1
16	10
17	75
18	350
19	1120
20	2130
21	2595
22	1730
23	690
24	80
25	1
26	1
27	15
28	165
29	1235
30	6930
31	27882
32	79825
33	162315
34	236490
35	245150
36	180936
37	91560
38	29890
39	5190
40	240
41	1

[1, 1, 1, 1, 3, 6, 1, 1, 6, 27, 60, 66, 24, 1, 1, 10, 75, 350, 1120, 2130, 2595, 1730, 690, 80, 1, 1, 15, 165, 1235, 6930, 27882, 79825, 162315, 236490, 245150, 180936, 91560, 29890, 5190, 240, 1]

cp's OEIS Frontend

A368569 Irregular triangle read by rows: T(n,k) is the number of essential graphs with n nodes and k (directed or undirected) edges (n >= 1, 0 <= k <= n*(n-1)/2).

Table of values

List of values