A287667 - cp's OEIS frontend

A287667 Number of set partitions of [n] such that j is member of block b only if b = 1 or at least one of j-1, ..., j-4 is member of a block >= b-1.

n	a(n)
0	1
1	1
2	2
3	5
4	15
5	52
6	203
7	876
8	4116
9	20827
10	112538
11	645045
12	3900512
13	24769152
14	164546915
15	1139818861
16	8209631792
17	61331709492
18	474221335902
19	3787741281763
20	31199052157724
21	264605708064825
22	2307562757319104
23	20666169125398768
24	189855243829576499

[1, 1, 2, 5, 15, 52, 203, 876, 4116, 20827, 112538, 645045, 3900512, 24769152, 164546915, 1139818861, 8209631792, 61331709492, 474221335902, 3787741281763, 31199052157724, 264605708064825, 2307562757319104, 20666169125398768, 189855243829576499]

cp's OEIS Frontend

A287667 Number of set partitions of [n] such that j is member of block b only if b = 1 or at least one of j-1, ..., j-4 is member of a block >= b-1.

Table of values

List of values