A372709 - cp's OEIS frontend

A372709 a(n) = Sum_{k=1..n} tau(n*k), where tau(n) = number of divisors of n, cf. A000005.

n	a(n)
1	1
2	5
3	9
4	18
5	19
6	41
7	31
8	56
9	59
10	83
11	57
12	136
13	73
14	127
15	151
16	170
17	103
18	233
19	119
20	270
21	239
22	233
23	151
24	406
25	241
26	285
27	311
28	424
29	205
30	579
31	225
32	464
33	425
34	399
35	473
36	758
37	283
38	459
39	517
40	812
41	319
42	891
43	339
44	742
45	853
46	587
47	375
48	1138
49	571
50	893
51	731
52	920
53	437
54	1157
55	847
56	1250

[1, 5, 9, 18, 19, 41, 31, 56, 59, 83, 57, 136, 73, 127, 151, 170, 103, 233, 119, 270, 239, 233, 151, 406, 241, 285, 311, 424, 205, 579, 225, 464, 425, 399, 473, 758, 283, 459, 517, 812, 319, 891, 339, 742, 853, 587, 375, 1138, 571, 893, 731, 920, 437, 1157, 847, 1250]

cp's OEIS Frontend

A372709 a(n) = Sum_{k=1..n} tau(n*k), where tau(n) = number of divisors of n, cf. A000005.

Table of values

List of values