A143396 - cp's OEIS frontend

A143396 Triangle T(n,k) = number of forests of labeled rooted trees of height at most 1, with n labels, k of which are used for root nodes and any root may contain >= 1 labels, n >= 0, 0<=k<=n.

n	a(n)
0	1
1	0
2	1
3	0
4	2
5	2
6	0
7	3
8	9
9	5
10	0
11	4
12	30
13	40
14	15
15	0
16	5
17	90
18	220
19	185
20	52
21	0
22	6
23	255
24	1040
25	1485
26	906
27	203
28	0
29	7
30	693
31	4550
32	9905
33	9891
34	4718
35	877
36	0
37	8
38	1820
39	19040
40	59850
41	87416
42	66808
43	26104
44	4140
45	0
46	9
47	4644
48	77448
49	341082
50	686826
51	750120
52	463212
53	153063
54	21147

[1, 0, 1, 0, 2, 2, 0, 3, 9, 5, 0, 4, 30, 40, 15, 0, 5, 90, 220, 185, 52, 0, 6, 255, 1040, 1485, 906, 203, 0, 7, 693, 4550, 9905, 9891, 4718, 877, 0, 8, 1820, 19040, 59850, 87416, 66808, 26104, 4140, 0, 9, 4644, 77448, 341082, 686826, 750120, 463212, 153063, 21147]

cp's OEIS Frontend

A143396 Triangle T(n,k) = number of forests of labeled rooted trees of height at most 1, with n labels, k of which are used for root nodes and any root may contain >= 1 labels, n >= 0, 0<=k<=n.

Table of values

List of values