A172148 - cp's OEIS frontend

A172148 Number of subsets S of {1,2,3,...,n} with the property that if x is a member of S then at least one of x/2 and 2x is also a member of S.

n	a(n)
1	1
2	2
3	2
4	4
5	4
6	8
7	8
8	14
9	14
10	28
11	28
12	56
13	56
14	112
15	112
16	192
17	192
18	384
19	384
20	768
21	768
22	1536
23	1536
24	2688
25	2688
26	5376
27	5376
28	10752
29	10752
30	21504
31	21504
32	37632
33	37632
34	75264
35	75264
36	150528
37	150528
38	301056
39	301056
40	526848
41	526848
42	1053696
43	1053696
44	2107392
45	2107392

[1, 2, 2, 4, 4, 8, 8, 14, 14, 28, 28, 56, 56, 112, 112, 192, 192, 384, 384, 768, 768, 1536, 1536, 2688, 2688, 5376, 5376, 10752, 10752, 21504, 21504, 37632, 37632, 75264, 75264, 150528, 150528, 301056, 301056, 526848, 526848, 1053696, 1053696, 2107392, 2107392]

cp's OEIS Frontend

A172148 Number of subsets S of {1,2,3,...,n} with the property that if x is a member of S then at least one of x/2 and 2x is also a member of S.

Table of values

List of values