A072490 - cp's OEIS frontend

A072490 Number of squarefree numbers (excluding 1) less than n.

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

[0, 0, 1, 2, 2, 3, 4, 5, 5, 5, 6, 7, 7, 8, 9, 10, 10, 11, 11, 12, 12, 13, 14, 15, 15, 15, 16, 16, 16, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 25, 26, 27, 28, 28, 28, 29, 30, 30, 30, 30, 31, 31, 32, 32, 33, 33, 34, 35, 36, 36, 37, 38, 38, 38, 39]

cp's OEIS Frontend

A072490 Number of squarefree numbers (excluding 1) less than n.

Table of values

List of values

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

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

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