A219026 - cp's OEIS frontend

A219026 Number of primes p<=n such that 2n-p and 2n+p-2 are both prime.

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	0
7	1
8	2
9	1
10	0
11	2
12	1
13	2
14	2
15	1
16	1
17	2
18	2
19	1
20	1
21	2
22	0
23	3
24	1
25	2
26	2
27	1
28	2
29	3
30	1
31	1
32	3
33	2
34	2
35	3
36	3
37	3
38	3
39	3
40	1
41	3
42	1
43	3
44	2
45	2
46	2
47	3
48	4
49	1
50	4
51	2
52	2
53	5
54	1
55	2
56	4
57	0
58	3
59	2
60	3
61	3
62	2
63	2
64	1
65	3
66	3
67	4
68	4
69	2
70	3
71	5
72	3
73	4
74	3
75	2
76	3
77	4
78	3
79	1
80	3
81	4
82	3
83	4
84	3
85	5
86	4
87	3
88	3
89	2
90	3
91	3
92	3
93	4
94	2
95	6
96	3
97	2
98	7
99	4
100	2

[0, 0, 1, 0, 2, 0, 1, 2, 1, 0, 2, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 0, 3, 1, 2, 2, 1, 2, 3, 1, 1, 3, 2, 2, 3, 3, 3, 3, 3, 1, 3, 1, 3, 2, 2, 2, 3, 4, 1, 4, 2, 2, 5, 1, 2, 4, 0, 3, 2, 3, 3, 2, 2, 1, 3, 3, 4, 4, 2, 3, 5, 3, 4, 3, 2, 3, 4, 3, 1, 3, 4, 3, 4, 3, 5, 4, 3, 3, 2, 3, 3, 3, 4, 2, 6, 3, 2, 7, 4, 2]

cp's OEIS Frontend

A219026 Number of primes p<=n such that 2n-p and 2n+p-2 are both prime.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	0
7	1
8	2
9	1
10	0
11	2
12	1
13	2
14	2
15	1
16	1
17	2
18	2
19	1
20	1
21	2
22	0
23	3
24	1
25	2
26	2
27	1
28	2
29	3
30	1
31	1
32	3
33	2
34	2
35	3
36	3
37	3
38	3
39	3
40	1
41	3
42	1
43	3
44	2
45	2
46	2
47	3
48	4
49	1
50	4
51	2
52	2
53	5
54	1
55	2
56	4
57	0
58	3
59	2
60	3
61	3
62	2
63	2
64	1
65	3
66	3
67	4
68	4
69	2
70	3
71	5
72	3
73	4
74	3
75	2
76	3
77	4
78	3
79	1
80	3
81	4
82	3
83	4
84	3
85	5
86	4
87	3
88	3
89	2
90	3
91	3
92	3
93	4
94	2
95	6
96	3
97	2
98	7
99	4
100	2

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	0
7	1
8	2
9	1
10	0
11	2
12	1
13	2
14	2
15	1
16	1
17	2
18	2
19	1
20	1
21	2
22	0
23	3
24	1
25	2
26	2
27	1
28	2
29	3
30	1
31	1
32	3
33	2
34	2
35	3
36	3
37	3
38	3
39	3
40	1
41	3
42	1
43	3
44	2
45	2
46	2
47	3
48	4
49	1
50	4
51	2
52	2
53	5
54	1
55	2
56	4
57	0
58	3
59	2
60	3
61	3
62	2
63	2
64	1
65	3
66	3
67	4
68	4
69	2
70	3
71	5
72	3
73	4
74	3
75	2
76	3
77	4
78	3
79	1
80	3
81	4
82	3
83	4
84	3
85	5
86	4
87	3
88	3
89	2
90	3
91	3
92	3
93	4
94	2
95	6
96	3
97	2
98	7
99	4
100	2

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	0
7	1
8	2
9	1
10	0
11	2
12	1
13	2
14	2
15	1
16	1
17	2
18	2
19	1
20	1
21	2
22	0
23	3
24	1
25	2
26	2
27	1
28	2
29	3
30	1
31	1
32	3
33	2
34	2
35	3
36	3
37	3
38	3
39	3
40	1
41	3
42	1
43	3
44	2
45	2
46	2
47	3
48	4
49	1
50	4
51	2
52	2
53	5
54	1
55	2
56	4
57	0
58	3
59	2
60	3
61	3
62	2
63	2
64	1
65	3
66	3
67	4
68	4
69	2
70	3
71	5
72	3
73	4
74	3
75	2
76	3
77	4
78	3
79	1
80	3
81	4
82	3
83	4
84	3
85	5
86	4
87	3
88	3
89	2
90	3
91	3
92	3
93	4
94	2
95	6
96	3
97	2
98	7
99	4
100	2