A293167 - cp's OEIS frontend

A293167 a(n) = Sum_{k = 1..n} d(d(d(k))), where d(k) is the number of divisors of k (A000005).

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	15
9	17
10	19
11	21
12	24
13	26
14	28
15	30
16	32
17	34
18	37
19	39
20	42
21	44
22	46
23	48
24	51
25	53
26	55
27	57
28	60
29	62
30	65
31	67
32	70
33	72
34	74
35	76
36	78
37	80
38	82
39	84
40	87
41	89
42	92
43	94
44	97
45	100
46	102
47	104
48	107
49	109
50	112
51	114
52	117
53	119
54	122
55	124
56	127
57	129
58	131
59	133
60	137
61	139
62	141
63	144
64	146
65	148
66	151
67	153
68	156
69	158

[1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 24, 26, 28, 30, 32, 34, 37, 39, 42, 44, 46, 48, 51, 53, 55, 57, 60, 62, 65, 67, 70, 72, 74, 76, 78, 80, 82, 84, 87, 89, 92, 94, 97, 100, 102, 104, 107, 109, 112, 114, 117, 119, 122, 124, 127, 129, 131, 133, 137, 139, 141, 144, 146, 148, 151, 153, 156, 158]

cp's OEIS Frontend

A293167 a(n) = Sum_{k = 1..n} d(d(d(k))), where d(k) is the number of divisors of k (A000005).

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	15
9	17
10	19
11	21
12	24
13	26
14	28
15	30
16	32
17	34
18	37
19	39
20	42
21	44
22	46
23	48
24	51
25	53
26	55
27	57
28	60
29	62
30	65
31	67
32	70
33	72
34	74
35	76
36	78
37	80
38	82
39	84
40	87
41	89
42	92
43	94
44	97
45	100
46	102
47	104
48	107
49	109
50	112
51	114
52	117
53	119
54	122
55	124
56	127
57	129
58	131
59	133
60	137
61	139
62	141
63	144
64	146
65	148
66	151
67	153
68	156
69	158

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	15
9	17
10	19
11	21
12	24
13	26
14	28
15	30
16	32
17	34
18	37
19	39
20	42
21	44
22	46
23	48
24	51
25	53
26	55
27	57
28	60
29	62
30	65
31	67
32	70
33	72
34	74
35	76
36	78
37	80
38	82
39	84
40	87
41	89
42	92
43	94
44	97
45	100
46	102
47	104
48	107
49	109
50	112
51	114
52	117
53	119
54	122
55	124
56	127
57	129
58	131
59	133
60	137
61	139
62	141
63	144
64	146
65	148
66	151
67	153
68	156
69	158

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	15
9	17
10	19
11	21
12	24
13	26
14	28
15	30
16	32
17	34
18	37
19	39
20	42
21	44
22	46
23	48
24	51
25	53
26	55
27	57
28	60
29	62
30	65
31	67
32	70
33	72
34	74
35	76
36	78
37	80
38	82
39	84
40	87
41	89
42	92
43	94
44	97
45	100
46	102
47	104
48	107
49	109
50	112
51	114
52	117
53	119
54	122
55	124
56	127
57	129
58	131
59	133
60	137
61	139
62	141
63	144
64	146
65	148
66	151
67	153
68	156
69	158