A384330 - cp's OEIS frontend

A384330 Number of distinct subsets S of [n] such that for all 1 <= k <= n, there exist elements x,y in S (not necessarily distinct) such that x*y = 2k.

n	a(n)
0	1
1	0
2	1
3	1
4	1
5	1
6	3
7	3
8	8
9	11
10	30
11	30
12	57
13	57
14	159
15	295
16	427
17	427
18	1033
19	1033
20	1973
21	3610
22	10427
23	10427
24	20575
25	28731
26	83535
27	142793
28	273755
29	273755
30	549946
31	549946
32	1245416
33	2289562
34	6665252
35	12386159
36	24210731
37	24210731
38	71150197
39	131657471
40	256115337
41	256115337

[1, 0, 1, 1, 1, 1, 3, 3, 8, 11, 30, 30, 57, 57, 159, 295, 427, 427, 1033, 1033, 1973, 3610, 10427, 10427, 20575, 28731, 83535, 142793, 273755, 273755, 549946, 549946, 1245416, 2289562, 6665252, 12386159, 24210731, 24210731, 71150197, 131657471, 256115337, 256115337]

cp's OEIS Frontend

A384330 Number of distinct subsets S of [n] such that for all 1 <= k <= n, there exist elements x,y in S (not necessarily distinct) such that x*y = 2k.

Table of values

List of values