A101787 - cp's OEIS frontend

A101787 a(n) = |S(n)| where S(n) = {i : 1 <= i <= n and 4i-1 and 8i-1 are primes}.

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

[1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10]

cp's OEIS Frontend

A101787 a(n) = |S(n)| where S(n) = {i : 1 <= i <= n and 4i-1 and 8i-1 are primes}.

Table of values

List of values

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

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

cp's OEIS Frontend

A101787 a(n) = |S(n)| where S(n) = {i : 1 <= i <= n and 4*i-1 and 8*i-1 are primes}.

Table of values

List of values

A101787 a(n) = |S(n)| where S(n) = {i : 1 <= i <= n and 4i-1 and 8i-1 are primes}.

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