A088326 - cp's OEIS frontend

A088326 Triangle T(n,k) (n>=1, 1<=k<=n) read by rows, giving number of Piet Hut's "coat-hanger" arrangements: unlabeled forests of rooted trees with n edges and k connected components, in which the outdegree of each node is <= 2 and the symmetric group acts on the components.

n	a(n)
1	1
2	1
3	1
4	2
5	1
6	1
7	3
8	3
9	1
10	1
11	6
12	5
13	3
14	1
15	1
16	11
17	12
18	6
19	3
20	1
21	1
22	23
23	23
24	14
25	6
26	3
27	1
28	1
29	46
30	52
31	29
32	15
33	6
34	3
35	1
36	1
37	98
38	109
39	68
40	31
41	15
42	6
43	3
44	1
45	1
46	207
47	244
48	147
49	74
50	32
51	15
52	6
53	3
54	1
55	1
56	451
57	532
58	337
59	163
60	76
61	32
62	15
63	6
64	3
65	1
66	1
67	983
68	1196
69	757
70	380
71	169
72	77
73	32
74	15
75	6
76	3
77	1
78	1

[1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 6, 5, 3, 1, 1, 11, 12, 6, 3, 1, 1, 23, 23, 14, 6, 3, 1, 1, 46, 52, 29, 15, 6, 3, 1, 1, 98, 109, 68, 31, 15, 6, 3, 1, 1, 207, 244, 147, 74, 32, 15, 6, 3, 1, 1, 451, 532, 337, 163, 76, 32, 15, 6, 3, 1, 1, 983, 1196, 757, 380, 169, 77, 32, 15, 6, 3, 1, 1]

cp's OEIS Frontend

A088326 Triangle T(n,k) (n>=1, 1<=k<=n) read by rows, giving number of Piet Hut's "coat-hanger" arrangements: unlabeled forests of rooted trees with n edges and k connected components, in which the outdegree of each node is <= 2 and the symmetric group acts on the components.

Table of values

List of values