A085398 - cp's OEIS frontend

A085398 Let Cn(x) be the n-th cyclotomic polynomial; a(n) is the least k>1 such that Cn(k) is prime.

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

[3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 5, 2, 2, 2, 2, 2, 2, 6, 2, 4, 3, 2, 10, 2, 22, 2, 2, 4, 6, 2, 2, 2, 2, 2, 14, 3, 61, 2, 10, 2, 14, 2, 15, 25, 11, 2, 5, 5, 2, 6, 30, 11, 24, 7, 7, 2, 5, 7, 19, 3, 2, 2, 3, 30, 2, 9, 46, 85, 2, 3, 3, 3, 11, 16, 59, 7, 2, 2, 22, 2, 21, 61, 41, 7, 2, 2, 8, 5, 2, 2]

cp's OEIS Frontend

A085398 Let Cn(x) be the n-th cyclotomic polynomial; a(n) is the least k>1 such that Cn(k) is prime.

Table of values

List of values

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

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

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