A128330 - cp's OEIS frontend

A128330 a(1)=1. a(n) = number of positive numbers <= n that are coprime to the product of the first n-1 terms of this sequence.

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

[1, 2, 2, 2, 3, 2, 3, 3, 3, 3, 4, 4, 5, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 6, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 11, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 16, 16, 16, 16, 16, 16, 17, 16, 16, 16, 17]

cp's OEIS Frontend

A128330 a(1)=1. a(n) = number of positive numbers <= n that are coprime to the product of the first n-1 terms of this sequence.

Table of values

List of values

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

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

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