A071838 - cp's OEIS frontend

A071838 a(n) = Pi(8,3)(n) + Pi(8,5)(n) - Pi(8,1)(n) - Pi(8,7)(n) where Pi(a,b)(x) denotes the number of primes in the arithmetic progression a*k + b less than or equal to x.

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	1
8	1
9	1
10	1
11	2
12	2
13	3
14	3
15	3
16	3
17	2
18	2
19	3
20	3
21	3
22	3
23	2
24	2
25	2
26	2
27	2
28	2
29	3
30	3
31	2
32	2
33	2
34	2
35	2
36	2
37	3
38	3
39	3
40	3
41	2
42	2
43	3
44	3
45	3
46	3
47	2
48	2
49	2
50	2
51	2
52	2
53	3
54	3
55	3
56	3
57	3
58	3
59	4
60	4
61	5
62	5
63	5
64	5
65	5
66	5
67	6
68	6
69	6
70	6
71	5
72	5
73	4
74	4
75	4
76	4
77	4
78	4
79	3
80	3
81	3
82	3
83	4
84	4
85	4
86	4
87	4
88	4
89	3
90	3
91	3
92	3
93	3
94	3
95	3
96	3
97	2
98	2
99	2
100	2
101	3
102	3
103	2
104	2
105	2

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

cp's OEIS Frontend

A071838 a(n) = Pi(8,3)(n) + Pi(8,5)(n) - Pi(8,1)(n) - Pi(8,7)(n) where Pi(a,b)(x) denotes the number of primes in the arithmetic progression a*k + b less than or equal to x.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	1
8	1
9	1
10	1
11	2
12	2
13	3
14	3
15	3
16	3
17	2
18	2
19	3
20	3
21	3
22	3
23	2
24	2
25	2
26	2
27	2
28	2
29	3
30	3
31	2
32	2
33	2
34	2
35	2
36	2
37	3
38	3
39	3
40	3
41	2
42	2
43	3
44	3
45	3
46	3
47	2
48	2
49	2
50	2
51	2
52	2
53	3
54	3
55	3
56	3
57	3
58	3
59	4
60	4
61	5
62	5
63	5
64	5
65	5
66	5
67	6
68	6
69	6
70	6
71	5
72	5
73	4
74	4
75	4
76	4
77	4
78	4
79	3
80	3
81	3
82	3
83	4
84	4
85	4
86	4
87	4
88	4
89	3
90	3
91	3
92	3
93	3
94	3
95	3
96	3
97	2
98	2
99	2
100	2
101	3
102	3
103	2
104	2
105	2

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	1
8	1
9	1
10	1
11	2
12	2
13	3
14	3
15	3
16	3
17	2
18	2
19	3
20	3
21	3
22	3
23	2
24	2
25	2
26	2
27	2
28	2
29	3
30	3
31	2
32	2
33	2
34	2
35	2
36	2
37	3
38	3
39	3
40	3
41	2
42	2
43	3
44	3
45	3
46	3
47	2
48	2
49	2
50	2
51	2
52	2
53	3
54	3
55	3
56	3
57	3
58	3
59	4
60	4
61	5
62	5
63	5
64	5
65	5
66	5
67	6
68	6
69	6
70	6
71	5
72	5
73	4
74	4
75	4
76	4
77	4
78	4
79	3
80	3
81	3
82	3
83	4
84	4
85	4
86	4
87	4
88	4
89	3
90	3
91	3
92	3
93	3
94	3
95	3
96	3
97	2
98	2
99	2
100	2
101	3
102	3
103	2
104	2
105	2

n	a(n)
1	0
2	0
3	1
4	1
5	2
6	2
7	1
8	1
9	1
10	1
11	2
12	2
13	3
14	3
15	3
16	3
17	2
18	2
19	3
20	3
21	3
22	3
23	2
24	2
25	2
26	2
27	2
28	2
29	3
30	3
31	2
32	2
33	2
34	2
35	2
36	2
37	3
38	3
39	3
40	3
41	2
42	2
43	3
44	3
45	3
46	3
47	2
48	2
49	2
50	2
51	2
52	2
53	3
54	3
55	3
56	3
57	3
58	3
59	4
60	4
61	5
62	5
63	5
64	5
65	5
66	5
67	6
68	6
69	6
70	6
71	5
72	5
73	4
74	4
75	4
76	4
77	4
78	4
79	3
80	3
81	3
82	3
83	4
84	4
85	4
86	4
87	4
88	4
89	3
90	3
91	3
92	3
93	3
94	3
95	3
96	3
97	2
98	2
99	2
100	2
101	3
102	3
103	2
104	2
105	2