A242345 - cp's OEIS frontend

A242345 Number of primes p < prime(n) with p and 2^p - p both primitive roots modulo prime(n).

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

[0, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 2, 2, 1, 4, 4, 7, 1, 2, 1, 1, 1, 6, 4, 1, 4, 2, 6, 3, 7, 1, 3, 7, 4, 6, 1, 5, 6, 9, 12, 7, 5, 6, 4, 11, 2, 3, 6, 12, 6, 18, 13, 3, 14, 13, 14, 15, 4, 9, 6, 3, 13, 8, 12, 5, 12, 6, 6, 20, 8, 14, 19, 8, 5, 5, 22, 20, 6, 18, 6]

cp's OEIS Frontend

A242345 Number of primes p < prime(n) with p and 2^p - p both primitive roots modulo prime(n).

Table of values

List of values

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

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

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