A119407 - cp's OEIS frontend

A119407 Number of nonempty subsets of {1,2,...,n} with no gap of length greater than 4 (a set S has a gap of length d if a and b are in S but no x with a < x < b is in S, where b-a=d).

n	a(n)
1	1
2	3
3	7
4	15
5	31
6	62
7	122
8	238
9	462
10	894
11	1727
12	3333
13	6429
14	12397
15	23901
16	46076
17	88820
18	171212
19	330028
20	636156
21	1226237
22	2363655
23	4556099
24	8782171
25	16928187
26	32630138
27	62896622
28	121237146
29	233692122
30	450456058
31	868281979
32	1673667337
33	3226097529
34	6218502937
35	11986549817
36	23104817656

[1, 3, 7, 15, 31, 62, 122, 238, 462, 894, 1727, 3333, 6429, 12397, 23901, 46076, 88820, 171212, 330028, 636156, 1226237, 2363655, 4556099, 8782171, 16928187, 32630138, 62896622, 121237146, 233692122, 450456058, 868281979, 1673667337, 3226097529, 6218502937, 11986549817, 23104817656]

cp's OEIS Frontend

A119407 Number of nonempty subsets of {1,2,...,n} with no gap of length greater than 4 (a set S has a gap of length d if a and b are in S but no x with a < x < b is in S, where b-a=d).

Table of values

List of values