A226982 - cp's OEIS frontend

A226982 a(n) = ceiling(n/2) - primepi(n).

n	a(n)
1	1
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	2
17	2
18	2
19	2
20	2
21	3
22	3
23	3
24	3
25	4
26	4
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	7
36	7
37	7
38	7
39	8
40	8
41	8
42	8
43	8
44	8
45	9
46	9
47	9
48	9
49	10
50	10
51	11
52	11
53	11
54	11
55	12
56	12
57	13
58	13
59	13
60	13
61	13
62	13
63	14
64	14
65	15
66	15
67	15

[1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 15, 15, 15]

cp's OEIS Frontend

A226982 a(n) = ceiling(n/2) - primepi(n).

Table of values

List of values

n	a(n)
1	1
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	2
17	2
18	2
19	2
20	2
21	3
22	3
23	3
24	3
25	4
26	4
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	7
36	7
37	7
38	7
39	8
40	8
41	8
42	8
43	8
44	8
45	9
46	9
47	9
48	9
49	10
50	10
51	11
52	11
53	11
54	11
55	12
56	12
57	13
58	13
59	13
60	13
61	13
62	13
63	14
64	14
65	15
66	15
67	15

n	a(n)
1	1
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	2
17	2
18	2
19	2
20	2
21	3
22	3
23	3
24	3
25	4
26	4
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	7
36	7
37	7
38	7
39	8
40	8
41	8
42	8
43	8
44	8
45	9
46	9
47	9
48	9
49	10
50	10
51	11
52	11
53	11
54	11
55	12
56	12
57	13
58	13
59	13
60	13
61	13
62	13
63	14
64	14
65	15
66	15
67	15

n	a(n)
1	1
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	1
14	1
15	2
16	2
17	2
18	2
19	2
20	2
21	3
22	3
23	3
24	3
25	4
26	4
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	7
36	7
37	7
38	7
39	8
40	8
41	8
42	8
43	8
44	8
45	9
46	9
47	9
48	9
49	10
50	10
51	11
52	11
53	11
54	11
55	12
56	12
57	13
58	13
59	13
60	13
61	13
62	13
63	14
64	14
65	15
66	15
67	15