A086389 - cp's OEIS frontend

A086389 Number of factors over Q in the factorization of U_n(x) - 1 where U_n(x) is the Chebyshev polynomial of the second kind.

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

[1, 1, 2, 3, 2, 3, 3, 4, 3, 4, 2, 6, 4, 3, 4, 6, 2, 6, 4, 6, 4, 4, 3, 8, 5, 4, 4, 8, 2, 7, 4, 6, 6, 5, 4, 9, 4, 4, 4, 10, 2, 8, 6, 6, 6, 4, 3, 11, 5, 6, 4, 8, 4, 8, 6, 8, 4, 6, 2, 12, 6, 3, 8, 9, 4, 8, 4, 8, 4, 9, 2, 12, 6, 4, 8, 8, 4, 8, 5, 10, 5, 6, 4, 12, 6]

cp's OEIS Frontend

A086389 Number of factors over Q in the factorization of U_n(x) - 1 where U_n(x) is the Chebyshev polynomial of the second kind.

Table of values

List of values

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

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

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