A163373 - cp's OEIS frontend

A163373 a(n) = phi(phi(sigma(n))).

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

[1, 1, 1, 2, 1, 2, 2, 4, 4, 2, 2, 4, 2, 4, 4, 8, 2, 8, 4, 4, 8, 4, 4, 8, 8, 4, 8, 8, 4, 8, 8, 12, 8, 6, 8, 24, 6, 8, 8, 8, 4, 16, 8, 8, 8, 8, 8, 16, 12, 16, 8, 12, 6, 16, 8, 16, 16, 8, 8, 16, 8, 16, 16, 36, 8, 16, 16, 12, 16, 16, 8, 32, 12, 12, 16, 16, 16, 16, 16]

cp's OEIS Frontend

A163373 a(n) = phi(phi(sigma(n))).

Table of values

List of values

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

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

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