A354257 - cp's OEIS frontend

A354257 a(n) is the smallest k such that there exists a degree-k primitive Dirichlet characters modulo n, or -1 no such k exists.

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

[1, -1, 2, 2, 2, -1, 2, 2, 3, -1, 2, 2, 2, -1, 2, 4, 2, -1, 2, 2, 2, -1, 2, 2, 5, -1, 9, 2, 2, -1, 2, 8, 2, -1, 2, 6, 2, -1, 2, 2, 2, -1, 2, 2, 6, -1, 2, 4, 7, -1, 2, 2, 2, -1, 2, 2, 2, -1, 2, 2, 2, -1, 3, 16, 2, -1, 2, 2, 2, -1, 2, 6, 2, -1, 10, 2, 2, -1, 2, 4, 27, -1, 2, 2, 2, -1, 2, 2, 2, -1]

cp's OEIS Frontend

A354257 a(n) is the smallest k such that there exists a degree-k primitive Dirichlet characters modulo n, or -1 no such k exists.

Table of values

List of values

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

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

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