A009213 - cp's OEIS frontend

A009213 a(n) = gcd(d(n), phi(n)), where d is the number of divisors of n (A000005) and phi is Euler's totient function (A000010).

n	a(n)
1	1
2	1
3	2
4	1
5	2
6	2
7	2
8	4
9	3
10	4
11	2
12	2
13	2
14	2
15	4
16	1
17	2
18	6
19	2
20	2
21	4
22	2
23	2
24	8
25	1
26	4
27	2
28	6
29	2
30	8
31	2
32	2
33	4
34	4
35	4
36	3
37	2
38	2
39	4
40	8
41	2
42	4
43	2
44	2
45	6
46	2
47	2
48	2
49	3
50	2
51	4
52	6
53	2
54	2
55	4
56	8
57	4
58	4
59	2
60	4
61	2
62	2
63	6
64	1
65	4
66	4
67	2
68	2
69	4
70	8
71	2
72	12
73	2
74	4
75	2
76	6
77	4
78	8
79	2
80	2
81	1
82	4
83	2
84	12
85	4
86	2
87	4
88	8
89	2
90	12
91	4
92	2
93	4
94	2
95	4
96	4
97	2
98	6
99	6
100	1
101	2
102	8
103	2
104	8
105	8

[1, 1, 2, 1, 2, 2, 2, 4, 3, 4, 2, 2, 2, 2, 4, 1, 2, 6, 2, 2, 4, 2, 2, 8, 1, 4, 2, 6, 2, 8, 2, 2, 4, 4, 4, 3, 2, 2, 4, 8, 2, 4, 2, 2, 6, 2, 2, 2, 3, 2, 4, 6, 2, 2, 4, 8, 4, 4, 2, 4, 2, 2, 6, 1, 4, 4, 2, 2, 4, 8, 2, 12, 2, 4, 2, 6, 4, 8, 2, 2, 1, 4, 2, 12, 4, 2, 4, 8, 2, 12, 4, 2, 4, 2, 4, 4, 2, 6, 6, 1, 2, 8, 2, 8, 8]

cp's OEIS Frontend

A009213 a(n) = gcd(d(n), phi(n)), where d is the number of divisors of n (A000005) and phi is Euler's totient function (A000010).

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	1
5	2
6	2
7	2
8	4
9	3
10	4
11	2
12	2
13	2
14	2
15	4
16	1
17	2
18	6
19	2
20	2
21	4
22	2
23	2
24	8
25	1
26	4
27	2
28	6
29	2
30	8
31	2
32	2
33	4
34	4
35	4
36	3
37	2
38	2
39	4
40	8
41	2
42	4
43	2
44	2
45	6
46	2
47	2
48	2
49	3
50	2
51	4
52	6
53	2
54	2
55	4
56	8
57	4
58	4
59	2
60	4
61	2
62	2
63	6
64	1
65	4
66	4
67	2
68	2
69	4
70	8
71	2
72	12
73	2
74	4
75	2
76	6
77	4
78	8
79	2
80	2
81	1
82	4
83	2
84	12
85	4
86	2
87	4
88	8
89	2
90	12
91	4
92	2
93	4
94	2
95	4
96	4
97	2
98	6
99	6
100	1
101	2
102	8
103	2
104	8
105	8

n	a(n)
1	1
2	1
3	2
4	1
5	2
6	2
7	2
8	4
9	3
10	4
11	2
12	2
13	2
14	2
15	4
16	1
17	2
18	6
19	2
20	2
21	4
22	2
23	2
24	8
25	1
26	4
27	2
28	6
29	2
30	8
31	2
32	2
33	4
34	4
35	4
36	3
37	2
38	2
39	4
40	8
41	2
42	4
43	2
44	2
45	6
46	2
47	2
48	2
49	3
50	2
51	4
52	6
53	2
54	2
55	4
56	8
57	4
58	4
59	2
60	4
61	2
62	2
63	6
64	1
65	4
66	4
67	2
68	2
69	4
70	8
71	2
72	12
73	2
74	4
75	2
76	6
77	4
78	8
79	2
80	2
81	1
82	4
83	2
84	12
85	4
86	2
87	4
88	8
89	2
90	12
91	4
92	2
93	4
94	2
95	4
96	4
97	2
98	6
99	6
100	1
101	2
102	8
103	2
104	8
105	8

n	a(n)
1	1
2	1
3	2
4	1
5	2
6	2
7	2
8	4
9	3
10	4
11	2
12	2
13	2
14	2
15	4
16	1
17	2
18	6
19	2
20	2
21	4
22	2
23	2
24	8
25	1
26	4
27	2
28	6
29	2
30	8
31	2
32	2
33	4
34	4
35	4
36	3
37	2
38	2
39	4
40	8
41	2
42	4
43	2
44	2
45	6
46	2
47	2
48	2
49	3
50	2
51	4
52	6
53	2
54	2
55	4
56	8
57	4
58	4
59	2
60	4
61	2
62	2
63	6
64	1
65	4
66	4
67	2
68	2
69	4
70	8
71	2
72	12
73	2
74	4
75	2
76	6
77	4
78	8
79	2
80	2
81	1
82	4
83	2
84	12
85	4
86	2
87	4
88	8
89	2
90	12
91	4
92	2
93	4
94	2
95	4
96	4
97	2
98	6
99	6
100	1
101	2
102	8
103	2
104	8
105	8