A124498 - cp's OEIS frontend

A124498 Triangle read by rows: T(n,k) is the number of set partitions of the set {1,2,...,n} containing k blocks of size 2 (0 <= k <= floor(n/2)).

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	3
6	6
7	6
8	3
9	17
10	20
11	15
12	53
13	90
14	45
15	15
16	205
17	357
18	210
19	105
20	871
21	1484
22	1260
23	420
24	105
25	3876
26	7380
27	6426
28	2520
29	945
30	18820
31	39195
32	33390
33	18900
34	4725
35	945
36	99585
37	213180
38	202950
39	117810
40	34650
41	10395
42	558847
43	1242120
44	1293435
45	734580
46	311850

[1, 1, 1, 1, 2, 3, 6, 6, 3, 17, 20, 15, 53, 90, 45, 15, 205, 357, 210, 105, 871, 1484, 1260, 420, 105, 3876, 7380, 6426, 2520, 945, 18820, 39195, 33390, 18900, 4725, 945, 99585, 213180, 202950, 117810, 34650, 10395, 558847, 1242120, 1293435, 734580, 311850]

cp's OEIS Frontend

A124498 Triangle read by rows: T(n,k) is the number of set partitions of the set {1,2,...,n} containing k blocks of size 2 (0 <= k <= floor(n/2)).

Table of values

List of values