A128487 - cp's OEIS frontend

A128487 Irregular array where n-th row is the positive integers < n which are coprime to exactly one distinct prime divisor of n.

n	a(n)
2	1
3	1
4	2
5	1
6	3
7	1
8	2
9	3
10	4
11	2
12	3
13	4
14	1
15	2
16	3
17	4
18	5
19	6
20	1
21	3
22	5
23	7
24	1
25	2
26	4
27	5
28	7
29	8
30	2
31	4
32	5
33	6
34	8
35	1
36	2
37	3
38	4
39	5
40	6
41	7
42	8
43	9
44	10
45	2
46	3
47	4
48	8
49	9
50	10
51	1
52	2
53	3
54	4
55	5
56	6
57	7
58	8
59	9
60	10
61	11
62	12
63	2
64	4
65	6
66	7
67	8
68	10
69	12
70	3
71	5
72	6
73	9
74	10
75	12
76	1
77	3
78	5
79	7
80	9
81	11
82	13
83	15
84	1
85	2
86	3
87	4
88	5
89	6
90	7
91	8
92	9
93	10
94	11
95	12
96	13
97	14

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

cp's OEIS Frontend

A128487 Irregular array where n-th row is the positive integers < n which are coprime to exactly one distinct prime divisor of n.

Table of values

List of values

n	a(n)
2	1
3	1
4	2
5	1
6	3
7	1
8	2
9	3
10	4
11	2
12	3
13	4
14	1
15	2
16	3
17	4
18	5
19	6
20	1
21	3
22	5
23	7
24	1
25	2
26	4
27	5
28	7
29	8
30	2
31	4
32	5
33	6
34	8
35	1
36	2
37	3
38	4
39	5
40	6
41	7
42	8
43	9
44	10
45	2
46	3
47	4
48	8
49	9
50	10
51	1
52	2
53	3
54	4
55	5
56	6
57	7
58	8
59	9
60	10
61	11
62	12
63	2
64	4
65	6
66	7
67	8
68	10
69	12
70	3
71	5
72	6
73	9
74	10
75	12
76	1
77	3
78	5
79	7
80	9
81	11
82	13
83	15
84	1
85	2
86	3
87	4
88	5
89	6
90	7
91	8
92	9
93	10
94	11
95	12
96	13
97	14

n	a(n)
2	1
3	1
4	2
5	1
6	3
7	1
8	2
9	3
10	4
11	2
12	3
13	4
14	1
15	2
16	3
17	4
18	5
19	6
20	1
21	3
22	5
23	7
24	1
25	2
26	4
27	5
28	7
29	8
30	2
31	4
32	5
33	6
34	8
35	1
36	2
37	3
38	4
39	5
40	6
41	7
42	8
43	9
44	10
45	2
46	3
47	4
48	8
49	9
50	10
51	1
52	2
53	3
54	4
55	5
56	6
57	7
58	8
59	9
60	10
61	11
62	12
63	2
64	4
65	6
66	7
67	8
68	10
69	12
70	3
71	5
72	6
73	9
74	10
75	12
76	1
77	3
78	5
79	7
80	9
81	11
82	13
83	15
84	1
85	2
86	3
87	4
88	5
89	6
90	7
91	8
92	9
93	10
94	11
95	12
96	13
97	14

n	a(n)
2	1
3	1
4	2
5	1
6	3
7	1
8	2
9	3
10	4
11	2
12	3
13	4
14	1
15	2
16	3
17	4
18	5
19	6
20	1
21	3
22	5
23	7
24	1
25	2
26	4
27	5
28	7
29	8
30	2
31	4
32	5
33	6
34	8
35	1
36	2
37	3
38	4
39	5
40	6
41	7
42	8
43	9
44	10
45	2
46	3
47	4
48	8
49	9
50	10
51	1
52	2
53	3
54	4
55	5
56	6
57	7
58	8
59	9
60	10
61	11
62	12
63	2
64	4
65	6
66	7
67	8
68	10
69	12
70	3
71	5
72	6
73	9
74	10
75	12
76	1
77	3
78	5
79	7
80	9
81	11
82	13
83	15
84	1
85	2
86	3
87	4
88	5
89	6
90	7
91	8
92	9
93	10
94	11
95	12
96	13
97	14