A013928 - cp's OEIS frontend

A013928 Number of (positive) squarefree numbers < n.

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

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

cp's OEIS Frontend

A013928 Number of (positive) squarefree numbers < n.

Table of values

List of values

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

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

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