A274869 - cp's OEIS frontend

A274869 Number of set partitions of [n] into exactly five blocks such that all odd elements are in blocks with an odd index and all even elements are in blocks with an even index.

n	a(n)
5	1
6	2
7	13
8	26
9	113
10	226
11	833
12	1666
13	5649
14	11298
15	36561
16	73122
17	230161
18	460322
19	1424401
20	2848802
21	8720657
22	17441314
23	53021969
24	106043938
25	320925969
26	641851938
27	1936736529
28	3873473058
29	11665150225
30	23330300450
31	70169841937
32	140339683874
33	421734846737

[1, 2, 13, 26, 113, 226, 833, 1666, 5649, 11298, 36561, 73122, 230161, 460322, 1424401, 2848802, 8720657, 17441314, 53021969, 106043938, 320925969, 641851938, 1936736529, 3873473058, 11665150225, 23330300450, 70169841937, 140339683874, 421734846737]

cp's OEIS Frontend

A274869 Number of set partitions of [n] into exactly five blocks such that all odd elements are in blocks with an odd index and all even elements are in blocks with an even index.

Table of values

List of values