A081305 - cp's OEIS frontend

A081305 Number of numbers m <= n with at least one prime factor greater than 2*spf(m), where spf(m) is the smallest prime factor of m (A020639).

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

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

cp's OEIS Frontend

A081305 Number of numbers m <= n with at least one prime factor greater than 2*spf(m), where spf(m) is the smallest prime factor of m (A020639).

Table of values

List of values

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

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

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