A341861 - cp's OEIS frontend

A341861 Number of primes among the (p-1)/2 numbers {2p+1, 4p+1, ..., (p-1)*p+1}, p = prime(n).

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

[1, 1, 2, 3, 4, 3, 2, 4, 4, 3, 4, 5, 7, 8, 5, 8, 7, 9, 9, 10, 11, 11, 12, 12, 14, 13, 13, 12, 15, 14, 14, 17, 15, 19, 18, 12, 19, 13, 19, 20, 22, 20, 24, 21, 15, 21, 21, 23, 25, 26, 23, 26, 26, 19, 23, 27, 24, 29, 27, 26, 28, 31, 29, 30, 25, 30, 30, 34, 31, 29, 35]

cp's OEIS Frontend

A341861 Number of primes among the (p-1)/2 numbers {2p+1, 4p+1, ..., (p-1)*p+1}, p = prime(n).

Table of values

List of values

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

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

cp's OEIS Frontend

A341861 Number of primes among the (p-1)/2 numbers {2*p+1, 4*p+1, ..., (p-1)*p+1}, p = prime(n).

Table of values

List of values

A341861 Number of primes among the (p-1)/2 numbers {2p+1, 4p+1, ..., (p-1)*p+1}, p = prime(n).

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