A307856 - cp's OEIS frontend

A307856 a(1) = a(2) = 1; a(n) = Sum_{1 < k < n, k not dividing n} a(k).

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	4
7	10
8	18
9	37
10	71
11	146
12	285
13	577
14	1143
15	2293
16	4570
17	9160
18	18277
19	36597
20	73118
21	146301
22	292466
23	585079
24	1169848
25	2340003
26	4679431
27	9359402
28	18717687
29	37436529
30	74870685
31	149743743
32	299482896
33	598970235
34	1197931456
35	2395872060
36	4791725527
37	9583469660
38	19166902722

[1, 1, 1, 1, 3, 4, 10, 18, 37, 71, 146, 285, 577, 1143, 2293, 4570, 9160, 18277, 36597, 73118, 146301, 292466, 585079, 1169848, 2340003, 4679431, 9359402, 18717687, 37436529, 74870685, 149743743, 299482896, 598970235, 1197931456, 2395872060, 4791725527, 9583469660, 19166902722]

cp's OEIS Frontend

A307856 a(1) = a(2) = 1; a(n) = Sum_{1 < k < n, k not dividing n} a(k).

Table of values

List of values