A086898 - cp's OEIS frontend

A086898 a(n) = Sum_{d|n} tau(d-1).

n	a(n)
1	0
2	1
3	2
4	3
5	3
6	5
7	4
8	5
9	6
10	7
11	4
12	9
13	6
14	7
15	9
16	9
17	5
18	11
19	6
20	11
21	12
22	9
23	4
24	13
25	11
26	10
27	10
28	13
29	6
30	17
31	8
32	11
33	12
34	10
35	11
36	19
37	9
38	9
39	12
40	17
41	8
42	19
43	8
44	13
45	19
46	11
47	4
48	19
49	14
50	18
51	13
52	16
53	6
54	17
55	15
56	19
57	16
58	11
59	4
60	25
61	12
62	11
63	20
64	17
65	16
66	23
67	8
68	14
69	12
70	21
71	8
72	25
73	12
74	12
75	21
76	17
77	14
78	22
79	8
80	23
81	20

[0, 1, 2, 3, 3, 5, 4, 5, 6, 7, 4, 9, 6, 7, 9, 9, 5, 11, 6, 11, 12, 9, 4, 13, 11, 10, 10, 13, 6, 17, 8, 11, 12, 10, 11, 19, 9, 9, 12, 17, 8, 19, 8, 13, 19, 11, 4, 19, 14, 18, 13, 16, 6, 17, 15, 19, 16, 11, 4, 25, 12, 11, 20, 17, 16, 23, 8, 14, 12, 21, 8, 25, 12, 12, 21, 17, 14, 22, 8, 23, 20]

cp's OEIS Frontend

A086898 a(n) = Sum_{d|n} tau(d-1).

Table of values

List of values

n	a(n)
1	0
2	1
3	2
4	3
5	3
6	5
7	4
8	5
9	6
10	7
11	4
12	9
13	6
14	7
15	9
16	9
17	5
18	11
19	6
20	11
21	12
22	9
23	4
24	13
25	11
26	10
27	10
28	13
29	6
30	17
31	8
32	11
33	12
34	10
35	11
36	19
37	9
38	9
39	12
40	17
41	8
42	19
43	8
44	13
45	19
46	11
47	4
48	19
49	14
50	18
51	13
52	16
53	6
54	17
55	15
56	19
57	16
58	11
59	4
60	25
61	12
62	11
63	20
64	17
65	16
66	23
67	8
68	14
69	12
70	21
71	8
72	25
73	12
74	12
75	21
76	17
77	14
78	22
79	8
80	23
81	20

n	a(n)
1	0
2	1
3	2
4	3
5	3
6	5
7	4
8	5
9	6
10	7
11	4
12	9
13	6
14	7
15	9
16	9
17	5
18	11
19	6
20	11
21	12
22	9
23	4
24	13
25	11
26	10
27	10
28	13
29	6
30	17
31	8
32	11
33	12
34	10
35	11
36	19
37	9
38	9
39	12
40	17
41	8
42	19
43	8
44	13
45	19
46	11
47	4
48	19
49	14
50	18
51	13
52	16
53	6
54	17
55	15
56	19
57	16
58	11
59	4
60	25
61	12
62	11
63	20
64	17
65	16
66	23
67	8
68	14
69	12
70	21
71	8
72	25
73	12
74	12
75	21
76	17
77	14
78	22
79	8
80	23
81	20

n	a(n)
1	0
2	1
3	2
4	3
5	3
6	5
7	4
8	5
9	6
10	7
11	4
12	9
13	6
14	7
15	9
16	9
17	5
18	11
19	6
20	11
21	12
22	9
23	4
24	13
25	11
26	10
27	10
28	13
29	6
30	17
31	8
32	11
33	12
34	10
35	11
36	19
37	9
38	9
39	12
40	17
41	8
42	19
43	8
44	13
45	19
46	11
47	4
48	19
49	14
50	18
51	13
52	16
53	6
54	17
55	15
56	19
57	16
58	11
59	4
60	25
61	12
62	11
63	20
64	17
65	16
66	23
67	8
68	14
69	12
70	21
71	8
72	25
73	12
74	12
75	21
76	17
77	14
78	22
79	8
80	23
81	20