A048983 - cp's OEIS frontend

A048983 As n runs through composite numbers, a(n) = number of composite d < n such that gcd(d,n) = 1.

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

[0, 0, 0, 2, 1, 0, 1, 3, 2, 0, 1, 5, 3, 0, 11, 4, 9, 4, 0, 5, 10, 6, 14, 2, 7, 13, 5, 1, 7, 11, 9, 2, 27, 6, 18, 10, 3, 25, 9, 21, 13, 1, 13, 19, 14, 31, 4, 14, 26, 7, 5, 16, 20, 16, 40, 5, 11, 32, 19, 3, 42, 20, 34, 18, 2, 49, 21, 37, 23, 49, 9, 18]

cp's OEIS Frontend

A048983 As n runs through composite numbers, a(n) = number of composite d < n such that gcd(d,n) = 1.

Table of values

List of values

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

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

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