A270492 - cp's OEIS frontend

A270492 a(n) = gcd(r) where r ranges over the orders of all subgroups whose direct product gives the multiplicative group modulo n.

n	a(n)
1	0
2	0
3	2
4	2
5	4
6	2
7	6
8	2
9	6
10	4
11	10
12	2
13	12
14	6
15	2
16	2
17	16
18	6
19	18
20	2
21	2
22	10
23	22
24	2
25	20
26	12
27	18
28	2
29	28
30	2
31	30
32	2
33	2
34	16
35	2
36	2
37	36
38	18
39	2
40	2
41	40
42	2
43	42
44	2
45	2
46	22
47	46
48	2
49	42
50	20
51	2
52	2
53	52
54	18
55	2
56	2
57	2
58	28
59	58
60	2
61	60
62	30
63	6
64	2
65	4
66	2
67	66
68	2
69	2
70	2
71	70
72	2
73	72
74	36
75	2
76	2
77	2
78	2
79	78
80	2
81	54
82	40
83	82
84	2
85	4
86	42
87	2
88	2
89	88
90	2
91	6
92	2

[0, 0, 2, 2, 4, 2, 6, 2, 6, 4, 10, 2, 12, 6, 2, 2, 16, 6, 18, 2, 2, 10, 22, 2, 20, 12, 18, 2, 28, 2, 30, 2, 2, 16, 2, 2, 36, 18, 2, 2, 40, 2, 42, 2, 2, 22, 46, 2, 42, 20, 2, 2, 52, 18, 2, 2, 2, 28, 58, 2, 60, 30, 6, 2, 4, 2, 66, 2, 2, 2, 70, 2, 72, 36, 2, 2, 2, 2, 78, 2, 54, 40, 82, 2, 4, 42, 2, 2, 88, 2, 6, 2]

cp's OEIS Frontend

A270492 a(n) = gcd(r) where r ranges over the orders of all subgroups whose direct product gives the multiplicative group modulo n.

Table of values

List of values

n	a(n)
1	0
2	0
3	2
4	2
5	4
6	2
7	6
8	2
9	6
10	4
11	10
12	2
13	12
14	6
15	2
16	2
17	16
18	6
19	18
20	2
21	2
22	10
23	22
24	2
25	20
26	12
27	18
28	2
29	28
30	2
31	30
32	2
33	2
34	16
35	2
36	2
37	36
38	18
39	2
40	2
41	40
42	2
43	42
44	2
45	2
46	22
47	46
48	2
49	42
50	20
51	2
52	2
53	52
54	18
55	2
56	2
57	2
58	28
59	58
60	2
61	60
62	30
63	6
64	2
65	4
66	2
67	66
68	2
69	2
70	2
71	70
72	2
73	72
74	36
75	2
76	2
77	2
78	2
79	78
80	2
81	54
82	40
83	82
84	2
85	4
86	42
87	2
88	2
89	88
90	2
91	6
92	2

n	a(n)
1	0
2	0
3	2
4	2
5	4
6	2
7	6
8	2
9	6
10	4
11	10
12	2
13	12
14	6
15	2
16	2
17	16
18	6
19	18
20	2
21	2
22	10
23	22
24	2
25	20
26	12
27	18
28	2
29	28
30	2
31	30
32	2
33	2
34	16
35	2
36	2
37	36
38	18
39	2
40	2
41	40
42	2
43	42
44	2
45	2
46	22
47	46
48	2
49	42
50	20
51	2
52	2
53	52
54	18
55	2
56	2
57	2
58	28
59	58
60	2
61	60
62	30
63	6
64	2
65	4
66	2
67	66
68	2
69	2
70	2
71	70
72	2
73	72
74	36
75	2
76	2
77	2
78	2
79	78
80	2
81	54
82	40
83	82
84	2
85	4
86	42
87	2
88	2
89	88
90	2
91	6
92	2

n	a(n)
1	0
2	0
3	2
4	2
5	4
6	2
7	6
8	2
9	6
10	4
11	10
12	2
13	12
14	6
15	2
16	2
17	16
18	6
19	18
20	2
21	2
22	10
23	22
24	2
25	20
26	12
27	18
28	2
29	28
30	2
31	30
32	2
33	2
34	16
35	2
36	2
37	36
38	18
39	2
40	2
41	40
42	2
43	42
44	2
45	2
46	22
47	46
48	2
49	42
50	20
51	2
52	2
53	52
54	18
55	2
56	2
57	2
58	28
59	58
60	2
61	60
62	30
63	6
64	2
65	4
66	2
67	66
68	2
69	2
70	2
71	70
72	2
73	72
74	36
75	2
76	2
77	2
78	2
79	78
80	2
81	54
82	40
83	82
84	2
85	4
86	42
87	2
88	2
89	88
90	2
91	6
92	2