A320554 - cp's OEIS frontend

A320554 Number of set partitions of [n] such that for each block b the smallest integer interval containing b has at most four elements and for at least one block c the smallest integer interval containing c has exactly four elements.

n	a(n)
4	5
5	17
6	45
7	121
8	336
9	901
10	2347
11	6014
12	15314
13	38766
14	97531
15	244054
16	608339
17	1511919
18	3748379
19	9273353
20	22901665
21	56477538
22	139114445
23	342325451
24	841676972
25	2067997764
26	5078117000
27	12463618356
28	30577931115
29	74993361731
30	183870516407
31	450708620604
32	1104563863868

[5, 17, 45, 121, 336, 901, 2347, 6014, 15314, 38766, 97531, 244054, 608339, 1511919, 3748379, 9273353, 22901665, 56477538, 139114445, 342325451, 841676972, 2067997764, 5078117000, 12463618356, 30577931115, 74993361731, 183870516407, 450708620604, 1104563863868]

cp's OEIS Frontend

A320554 Number of set partitions of [n] such that for each block b the smallest integer interval containing b has at most four elements and for at least one block c the smallest integer interval containing c has exactly four elements.

Table of values

List of values