A216647 - cp's OEIS frontend

A216647 a(n) := card{cos((2^(k-1))*Pi/n): k=1,2,...}.

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

[2, 3, 2, 4, 3, 3, 4, 5, 4, 4, 6, 4, 7, 5, 5, 6, 5, 5, 10, 5, 7, 7, 12, 5, 11, 8, 10, 6, 15, 6, 6, 7, 6, 6, 13, 6, 19, 11, 13, 6, 11, 8, 8, 8, 13, 13, 24, 6, 22, 12, 9, 9, 27, 11, 21, 7, 10, 16, 30, 7, 31, 7, 7, 8, 7, 7, 34, 7, 23, 14, 36, 7]

cp's OEIS Frontend

A216647 a(n) := card{cos((2^(k-1))*Pi/n): k=1,2,...}.

Table of values

List of values

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

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

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