A065855 - cp's OEIS frontend

A065855 Number of composites <= n.

n	a(n)
1	0
2	0
3	0
4	1
5	1
6	2
7	2
8	3
9	4
10	5
11	5
12	6
13	6
14	7
15	8
16	9
17	9
18	10
19	10
20	11
21	12
22	13
23	13
24	14
25	15
26	16
27	17
28	18
29	18
30	19
31	19
32	20
33	21
34	22
35	23
36	24
37	24
38	25
39	26
40	27
41	27
42	28
43	28
44	29
45	30
46	31
47	31
48	32
49	33
50	34
51	35
52	36
53	36
54	37
55	38
56	39
57	40
58	41
59	41
60	42
61	42
62	43
63	44
64	45
65	46
66	47
67	47
68	48
69	49
70	50
71	50
72	51
73	51
74	52
75	53

[0, 0, 0, 1, 1, 2, 2, 3, 4, 5, 5, 6, 6, 7, 8, 9, 9, 10, 10, 11, 12, 13, 13, 14, 15, 16, 17, 18, 18, 19, 19, 20, 21, 22, 23, 24, 24, 25, 26, 27, 27, 28, 28, 29, 30, 31, 31, 32, 33, 34, 35, 36, 36, 37, 38, 39, 40, 41, 41, 42, 42, 43, 44, 45, 46, 47, 47, 48, 49, 50, 50, 51, 51, 52, 53]

cp's OEIS Frontend

A065855 Number of composites <= n.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	1
5	1
6	2
7	2
8	3
9	4
10	5
11	5
12	6
13	6
14	7
15	8
16	9
17	9
18	10
19	10
20	11
21	12
22	13
23	13
24	14
25	15
26	16
27	17
28	18
29	18
30	19
31	19
32	20
33	21
34	22
35	23
36	24
37	24
38	25
39	26
40	27
41	27
42	28
43	28
44	29
45	30
46	31
47	31
48	32
49	33
50	34
51	35
52	36
53	36
54	37
55	38
56	39
57	40
58	41
59	41
60	42
61	42
62	43
63	44
64	45
65	46
66	47
67	47
68	48
69	49
70	50
71	50
72	51
73	51
74	52
75	53

n	a(n)
1	0
2	0
3	0
4	1
5	1
6	2
7	2
8	3
9	4
10	5
11	5
12	6
13	6
14	7
15	8
16	9
17	9
18	10
19	10
20	11
21	12
22	13
23	13
24	14
25	15
26	16
27	17
28	18
29	18
30	19
31	19
32	20
33	21
34	22
35	23
36	24
37	24
38	25
39	26
40	27
41	27
42	28
43	28
44	29
45	30
46	31
47	31
48	32
49	33
50	34
51	35
52	36
53	36
54	37
55	38
56	39
57	40
58	41
59	41
60	42
61	42
62	43
63	44
64	45
65	46
66	47
67	47
68	48
69	49
70	50
71	50
72	51
73	51
74	52
75	53

n	a(n)
1	0
2	0
3	0
4	1
5	1
6	2
7	2
8	3
9	4
10	5
11	5
12	6
13	6
14	7
15	8
16	9
17	9
18	10
19	10
20	11
21	12
22	13
23	13
24	14
25	15
26	16
27	17
28	18
29	18
30	19
31	19
32	20
33	21
34	22
35	23
36	24
37	24
38	25
39	26
40	27
41	27
42	28
43	28
44	29
45	30
46	31
47	31
48	32
49	33
50	34
51	35
52	36
53	36
54	37
55	38
56	39
57	40
58	41
59	41
60	42
61	42
62	43
63	44
64	45
65	46
66	47
67	47
68	48
69	49
70	50
71	50
72	51
73	51
74	52
75	53