A086685 - cp's OEIS frontend

A086685 Number of 1 <= i < n such that i*n+1 is prime.

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

[0, 1, 1, 2, 1, 4, 2, 2, 3, 5, 3, 6, 4, 5, 5, 5, 3, 10, 2, 6, 6, 9, 4, 9, 5, 9, 7, 11, 4, 17, 3, 10, 9, 12, 9, 15, 4, 9, 11, 13, 5, 21, 7, 11, 10, 16, 8, 19, 6, 18, 13, 17, 5, 23, 10, 18, 9, 16, 8, 27, 7, 15, 13, 16, 13, 29, 9, 18, 13, 27, 9, 26, 10, 19, 18, 17, 11, 29, 11, 23, 18, 22, 11, 32]

cp's OEIS Frontend

A086685 Number of 1 <= i < n such that i*n+1 is prime.

Table of values

List of values

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

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

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