A320225 - cp's OEIS frontend

A320225 a(1) = 1; a(n > 1) = Sum_{k = 1..n} Sum_{d|k, d < k} a(d).

n	a(n)
1	1
2	1
3	2
4	4
5	5
6	9
7	10
8	16
9	19
10	26
11	27
12	44
13	45
14	57
15	65
16	87
17	88
18	120
19	121
20	158
21	171
22	200
23	201
24	278
25	284
26	331
27	353
28	426
29	427
30	536
31	537
32	646
33	676
34	766
35	782
36	982
37	983
38	1106
39	1154
40	1365
41	1366
42	1617
43	1618
44	1851
45	1943
46	2146
47	2147
48	2589
49	2600
50	2917
51	3008
52	3390
53	3391

[1, 1, 2, 4, 5, 9, 10, 16, 19, 26, 27, 44, 45, 57, 65, 87, 88, 120, 121, 158, 171, 200, 201, 278, 284, 331, 353, 426, 427, 536, 537, 646, 676, 766, 782, 982, 983, 1106, 1154, 1365, 1366, 1617, 1618, 1851, 1943, 2146, 2147, 2589, 2600, 2917, 3008, 3390, 3391]

cp's OEIS Frontend

A320225 a(1) = 1; a(n > 1) = Sum_{k = 1..n} Sum_{d|k, d < k} a(d).

Table of values

List of values