A274836 - cp's OEIS frontend

A274836 Number of set partitions of [n] such that the difference between each element and its block index is a multiple of three.

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	3
6	4
7	9
8	18
9	33
10	89
11	215
12	481
13	1486
14	4187
15	10974
16	37907
17	121114
18	362953
19	1385575
20	4924557
21	16494655
22	68685792
23	268113185
24	990074770
25	4455129525
26	18896355932
27	76116156873
28	367577989487
29	1679905933299
30	7313571105815
31	37669220146964

[1, 1, 1, 1, 2, 3, 4, 9, 18, 33, 89, 215, 481, 1486, 4187, 10974, 37907, 121114, 362953, 1385575, 4924557, 16494655, 68685792, 268113185, 990074770, 4455129525, 18896355932, 76116156873, 367577989487, 1679905933299, 7313571105815, 37669220146964]

cp's OEIS Frontend

A274836 Number of set partitions of [n] such that the difference between each element and its block index is a multiple of three.

Table of values

List of values