A219839 - cp's OEIS frontend

A219839 a(n) is the number of odd integers in 2..(n-1) that have a common factor (other than 1) with n.

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

[0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 2, 0, 1, 3, 0, 0, 3, 0, 2, 4, 1, 0, 4, 2, 1, 4, 2, 0, 7, 0, 0, 6, 1, 5, 6, 0, 1, 7, 4, 0, 9, 0, 2, 10, 1, 0, 8, 3, 5, 9, 2, 0, 9, 7, 4, 10, 1, 0, 14, 0, 1, 13, 0, 8, 13, 0, 2, 12, 11, 0, 12, 0, 1, 17, 2, 8, 15, 0, 8, 13, 1, 0, 18]

cp's OEIS Frontend

A219839 a(n) is the number of odd integers in 2..(n-1) that have a common factor (other than 1) with n.

Table of values

List of values

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

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

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