A072000 - cp's OEIS frontend

A072000 Number of semiprimes (A001358) <= n.

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

[0, 0, 0, 1, 1, 2, 2, 2, 3, 4, 4, 4, 4, 5, 6, 6, 6, 6, 6, 6, 7, 8, 8, 8, 9, 10, 10, 10, 10, 10, 10, 10, 11, 12, 13, 13, 13, 14, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 17, 17, 18, 18, 18, 18, 19, 19, 20, 21, 21, 21, 21, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 24, 25, 25, 25, 26]

cp's OEIS Frontend

A072000 Number of semiprimes (A001358) <= 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	2
9	3
10	4
11	4
12	4
13	4
14	5
15	6
16	6
17	6
18	6
19	6
20	6
21	7
22	8
23	8
24	8
25	9
26	10
27	10
28	10
29	10
30	10
31	10
32	10
33	11
34	12
35	13
36	13
37	13
38	14
39	15
40	15
41	15
42	15
43	15
44	15
45	15
46	16
47	16
48	16
49	17
50	17
51	18
52	18
53	18
54	18
55	19
56	19
57	20
58	21
59	21
60	21
61	21
62	22
63	22
64	22
65	23
66	23
67	23
68	23
69	24
70	24
71	24
72	24
73	24
74	25
75	25
76	25
77	26

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

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