A160438 - cp's OEIS frontend

A160438 Number of partitions of n*(n+1)/2 with at most four parts that can be obtained from grouping (with parentheses) a permutation of the sum 1+2+...+n.

n	a(n)
0	1
1	1
2	2
3	5
4	13
5	35
6	93
7	215
8	437
9	815
10	1436
11	2413
12	3886
13	6041
14	9125
15	13436
16	19323
17	27221
18	37670
19	51293
20	68797
21	91025
22	118982
23	153797
24	196721
25	249206
26	312935
27	389761
28	481709
29	591080
30	720485
31	872763
32	1050980
33	1258565
34	1499351
35	1777462

[1, 1, 2, 5, 13, 35, 93, 215, 437, 815, 1436, 2413, 3886, 6041, 9125, 13436, 19323, 27221, 37670, 51293, 68797, 91025, 118982, 153797, 196721, 249206, 312935, 389761, 481709, 591080, 720485, 872763, 1050980, 1258565, 1499351, 1777462]

cp's OEIS Frontend

A160438 Number of partitions of n*(n+1)/2 with at most four parts that can be obtained from grouping (with parentheses) a permutation of the sum 1+2+...+n.

Table of values

List of values