A049822 - cp's OEIS frontend

A049822 a(n) = 1 - tau(n) + Sum_{d|n} tau(d-1).

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	3
8	2
9	4
10	4
11	3
12	4
13	5
14	4
15	6
16	5
17	4
18	6
19	5
20	6
21	9
22	6
23	3
24	6
25	9
26	7
27	7
28	8
29	5
30	10
31	7
32	6
33	9
34	7
35	8
36	11
37	8
38	6
39	9
40	10
41	7
42	12
43	7
44	8
45	14
46	8
47	3
48	10
49	12
50	13
51	10
52	11
53	5
54	10
55	12
56	12
57	13
58	8
59	3
60	14
61	11
62	8
63	15
64	11
65	13
66	16
67	7
68	9
69	9
70	14
71	7
72	14
73	11
74	9
75	16
76	12
77	11
78	15
79	7
80	14
81	16
82	11
83	3
84	18
85	17
86	10
87	9
88	12

[0, 0, 1, 1, 2, 2, 3, 2, 4, 4, 3, 4, 5, 4, 6, 5, 4, 6, 5, 6, 9, 6, 3, 6, 9, 7, 7, 8, 5, 10, 7, 6, 9, 7, 8, 11, 8, 6, 9, 10, 7, 12, 7, 8, 14, 8, 3, 10, 12, 13, 10, 11, 5, 10, 12, 12, 13, 8, 3, 14, 11, 8, 15, 11, 13, 16, 7, 9, 9, 14, 7, 14, 11, 9, 16, 12, 11, 15, 7, 14, 16, 11, 3, 18, 17, 10, 9, 12]

cp's OEIS Frontend

A049822 a(n) = 1 - tau(n) + Sum_{d|n} tau(d-1).

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	3
8	2
9	4
10	4
11	3
12	4
13	5
14	4
15	6
16	5
17	4
18	6
19	5
20	6
21	9
22	6
23	3
24	6
25	9
26	7
27	7
28	8
29	5
30	10
31	7
32	6
33	9
34	7
35	8
36	11
37	8
38	6
39	9
40	10
41	7
42	12
43	7
44	8
45	14
46	8
47	3
48	10
49	12
50	13
51	10
52	11
53	5
54	10
55	12
56	12
57	13
58	8
59	3
60	14
61	11
62	8
63	15
64	11
65	13
66	16
67	7
68	9
69	9
70	14
71	7
72	14
73	11
74	9
75	16
76	12
77	11
78	15
79	7
80	14
81	16
82	11
83	3
84	18
85	17
86	10
87	9
88	12

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	3
8	2
9	4
10	4
11	3
12	4
13	5
14	4
15	6
16	5
17	4
18	6
19	5
20	6
21	9
22	6
23	3
24	6
25	9
26	7
27	7
28	8
29	5
30	10
31	7
32	6
33	9
34	7
35	8
36	11
37	8
38	6
39	9
40	10
41	7
42	12
43	7
44	8
45	14
46	8
47	3
48	10
49	12
50	13
51	10
52	11
53	5
54	10
55	12
56	12
57	13
58	8
59	3
60	14
61	11
62	8
63	15
64	11
65	13
66	16
67	7
68	9
69	9
70	14
71	7
72	14
73	11
74	9
75	16
76	12
77	11
78	15
79	7
80	14
81	16
82	11
83	3
84	18
85	17
86	10
87	9
88	12

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	3
8	2
9	4
10	4
11	3
12	4
13	5
14	4
15	6
16	5
17	4
18	6
19	5
20	6
21	9
22	6
23	3
24	6
25	9
26	7
27	7
28	8
29	5
30	10
31	7
32	6
33	9
34	7
35	8
36	11
37	8
38	6
39	9
40	10
41	7
42	12
43	7
44	8
45	14
46	8
47	3
48	10
49	12
50	13
51	10
52	11
53	5
54	10
55	12
56	12
57	13
58	8
59	3
60	14
61	11
62	8
63	15
64	11
65	13
66	16
67	7
68	9
69	9
70	14
71	7
72	14
73	11
74	9
75	16
76	12
77	11
78	15
79	7
80	14
81	16
82	11
83	3
84	18
85	17
86	10
87	9
88	12