A071181 - cp's OEIS frontend

A071181 Number of numbers k such that phi(k) divides phi(n).

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

[2, 2, 5, 5, 9, 5, 9, 9, 9, 9, 7, 9, 19, 9, 14, 14, 20, 9, 13, 14, 19, 7, 7, 14, 16, 19, 13, 19, 11, 14, 13, 20, 16, 20, 34, 19, 31, 13, 34, 20, 30, 19, 13, 16, 34, 7, 7, 20, 13, 16, 27, 34, 11, 13, 30, 34, 31, 11, 7, 20, 37, 13, 31, 27, 51, 16, 13, 27, 14, 34, 9, 34, 63, 31, 30, 31]

cp's OEIS Frontend

A071181 Number of numbers k such that phi(k) divides phi(n).

Table of values

List of values

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

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

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