A324986 - cp's OEIS frontend

A324986 a(n) = Sum_{d|n} (tau(d)*sigma(d)) where tau(k) = the number of divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).

n	a(n)
1	1
2	7
3	9
4	28
5	13
6	63
7	17
8	88
9	48
10	91
11	25
12	252
13	29
14	119
15	117
16	243
17	37
18	336
19	41
20	364
21	153
22	175
23	49
24	792
25	106
26	203
27	208
28	476
29	61
30	819
31	65
32	621
33	225
34	259
35	221
36	1344
37	77
38	287
39	261
40	1144
41	85
42	1071
43	89
44	700
45	624
46	343
47	97
48	2187
49	188
50	742
51	333
52	812
53	109
54	1456
55	325
56	1496

[1, 7, 9, 28, 13, 63, 17, 88, 48, 91, 25, 252, 29, 119, 117, 243, 37, 336, 41, 364, 153, 175, 49, 792, 106, 203, 208, 476, 61, 819, 65, 621, 225, 259, 221, 1344, 77, 287, 261, 1144, 85, 1071, 89, 700, 624, 343, 97, 2187, 188, 742, 333, 812, 109, 1456, 325, 1496]

cp's OEIS Frontend

A324986 a(n) = Sum_{d|n} (tau(d)*sigma(d)) where tau(k) = the number of divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).

Table of values

List of values