A073725 - cp's OEIS frontend

A073725 a(n)-th composite number = phi(n-th composite number); a(1)=a(2)=0.

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

[0, 0, 1, 2, 1, 1, 2, 3, 3, 2, 3, 6, 5, 3, 11, 6, 10, 6, 3, 9, 11, 9, 14, 6, 10, 14, 9, 6, 11, 14, 13, 9, 28, 11, 20, 14, 10, 27, 14, 24, 18, 9, 19, 24, 20, 32, 11, 20, 29, 14, 14, 24, 27, 24, 42, 14, 20, 37, 27, 14, 45, 28, 39, 27, 14, 51, 29, 42, 31, 51, 20, 28, 42, 27, 20, 32, 32]

cp's OEIS Frontend

A073725 a(n)-th composite number = phi(n-th composite number); a(1)=a(2)=0.

Table of values

List of values

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

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

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