A063124 - cp's OEIS frontend

A063124 a(n) = # { primes p | prime(n) <= p < 2*prime(n) } where prime(n) is the n-th prime.

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

[2, 2, 2, 3, 4, 4, 5, 5, 6, 7, 8, 10, 10, 10, 10, 12, 14, 13, 14, 15, 14, 16, 16, 17, 20, 21, 20, 20, 19, 19, 24, 24, 26, 26, 28, 27, 29, 29, 29, 29, 31, 31, 33, 33, 33, 33, 36, 39, 39, 39, 40, 40, 40, 42, 43, 44, 43, 43, 43, 43, 43, 45, 50, 51, 50, 50, 55, 55, 57, 56, 56, 56, 58]

cp's OEIS Frontend

A063124 a(n) = # { primes p | prime(n) <= p < 2*prime(n) } where prime(n) is the n-th prime.

Table of values

List of values

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

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

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