A013940 - cp's OEIS frontend

A013940 a(n) = Sum_{k=1..n} floor(n/prime(k)^2).

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

[0, 0, 0, 1, 1, 1, 1, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 6, 6, 7, 7, 7, 7, 8, 9, 9, 10, 11, 11, 11, 11, 12, 12, 12, 12, 14, 14, 14, 14, 15, 15, 15, 15, 16, 17, 17, 17, 18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 23, 23, 24, 24, 24, 25, 26, 26, 26, 26, 27, 27, 27, 27, 29]

cp's OEIS Frontend

A013940 a(n) = Sum_{k=1..n} floor(n/prime(k)^2).

Table of values

List of values

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

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

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