A320438 - cp's OEIS frontend

A320438 Irregular triangle read by rows where T(n,k) is the number of set partitions of {1,...,n} with all block-sums equal to d, where d is the k-th divisor of n*(n+1)/2 that is >= n.

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	1
12	4
13	1
14	1
15	3
16	7
17	1
18	1
19	9
20	1
21	1
22	1
23	1
24	43
25	35
26	1
27	1
28	102
29	62
30	1
31	1
32	1
33	1
34	68
35	595
36	1
37	1
38	17
39	187
40	871
41	1480
42	361
43	1
44	1
45	2650
46	657
47	1
48	1
49	9294
50	1
51	1
52	23728
53	1
54	1
55	27763
56	4110
57	1
58	1
59	1850
60	25035
61	108516
62	157991
63	7636
64	1
65	1
66	11421
67	411474
68	1

[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 3, 7, 1, 1, 9, 1, 1, 1, 1, 43, 35, 1, 1, 102, 62, 1, 1, 1, 1, 68, 595, 1, 1, 17, 187, 871, 1480, 361, 1, 1, 2650, 657, 1, 1, 9294, 1, 1, 23728, 1, 1, 27763, 4110, 1, 1, 1850, 25035, 108516, 157991, 7636, 1, 1, 11421, 411474, 1]

cp's OEIS Frontend

A320438 Irregular triangle read by rows where T(n,k) is the number of set partitions of {1,...,n} with all block-sums equal to d, where d is the k-th divisor of n*(n+1)/2 that is >= n.

Table of values

List of values