A360480 - cp's OEIS frontend

A360480 a(n) = number of numbers k < n, with gcd(k, n) > 1, such that there is at least one prime divisor p | k that does not divide n, and at least one prime divisor q | n that does not divide k.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	0
12	1
13	0
14	3
15	3
16	0
17	0
18	3
19	0
20	5
21	5
22	6
23	0
24	6
25	0
26	8
27	0
28	9
29	0
30	5
31	0
32	0
33	8
34	11
35	7
36	10
37	0
38	13
39	10
40	13
41	0
42	12
43	0
44	16
45	13
46	17
47	0
48	16
49	0
50	18
51	14
52	20
53	0
54	19
55	11
56	21
57	16
58	23
59	0
60	19
61	0
62	25
63	19
64	0
65	13
66	25
67	0
68	27
69	20
70	27
71	0
72	27
73	0
74	30
75	25
76	31
77	13
78	32
79	0
80	32
81	0
82	34
83	0
84	33
85	17
86	36
87	25
88	37

[0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 3, 3, 0, 0, 3, 0, 5, 5, 6, 0, 6, 0, 8, 0, 9, 0, 5, 0, 0, 8, 11, 7, 10, 0, 13, 10, 13, 0, 12, 0, 16, 13, 17, 0, 16, 0, 18, 14, 20, 0, 19, 11, 21, 16, 23, 0, 19, 0, 25, 19, 0, 13, 25, 0, 27, 20, 27, 0, 27, 0, 30, 25, 31, 13, 32, 0, 32, 0, 34, 0, 33, 17, 36, 25, 37]

cp's OEIS Frontend

A360480 a(n) = number of numbers k < n, with gcd(k, n) > 1, such that there is at least one prime divisor p | k that does not divide n, and at least one prime divisor q | n that does not divide k.

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	0
12	1
13	0
14	3
15	3
16	0
17	0
18	3
19	0
20	5
21	5
22	6
23	0
24	6
25	0
26	8
27	0
28	9
29	0
30	5
31	0
32	0
33	8
34	11
35	7
36	10
37	0
38	13
39	10
40	13
41	0
42	12
43	0
44	16
45	13
46	17
47	0
48	16
49	0
50	18
51	14
52	20
53	0
54	19
55	11
56	21
57	16
58	23
59	0
60	19
61	0
62	25
63	19
64	0
65	13
66	25
67	0
68	27
69	20
70	27
71	0
72	27
73	0
74	30
75	25
76	31
77	13
78	32
79	0
80	32
81	0
82	34
83	0
84	33
85	17
86	36
87	25
88	37

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	0
12	1
13	0
14	3
15	3
16	0
17	0
18	3
19	0
20	5
21	5
22	6
23	0
24	6
25	0
26	8
27	0
28	9
29	0
30	5
31	0
32	0
33	8
34	11
35	7
36	10
37	0
38	13
39	10
40	13
41	0
42	12
43	0
44	16
45	13
46	17
47	0
48	16
49	0
50	18
51	14
52	20
53	0
54	19
55	11
56	21
57	16
58	23
59	0
60	19
61	0
62	25
63	19
64	0
65	13
66	25
67	0
68	27
69	20
70	27
71	0
72	27
73	0
74	30
75	25
76	31
77	13
78	32
79	0
80	32
81	0
82	34
83	0
84	33
85	17
86	36
87	25
88	37

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	0
12	1
13	0
14	3
15	3
16	0
17	0
18	3
19	0
20	5
21	5
22	6
23	0
24	6
25	0
26	8
27	0
28	9
29	0
30	5
31	0
32	0
33	8
34	11
35	7
36	10
37	0
38	13
39	10
40	13
41	0
42	12
43	0
44	16
45	13
46	17
47	0
48	16
49	0
50	18
51	14
52	20
53	0
54	19
55	11
56	21
57	16
58	23
59	0
60	19
61	0
62	25
63	19
64	0
65	13
66	25
67	0
68	27
69	20
70	27
71	0
72	27
73	0
74	30
75	25
76	31
77	13
78	32
79	0
80	32
81	0
82	34
83	0
84	33
85	17
86	36
87	25
88	37