A048984 - cp's OEIS frontend

A048984 As n runs through composite numbers, a(n) = number of nonprime d < n such that gcd(d,n) = 1.

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

[1, 1, 1, 3, 2, 1, 2, 4, 3, 1, 2, 6, 4, 1, 12, 5, 10, 5, 1, 6, 11, 7, 15, 3, 8, 14, 6, 2, 8, 12, 10, 3, 28, 7, 19, 11, 4, 26, 10, 22, 14, 2, 14, 20, 15, 32, 5, 15, 27, 8, 6, 17, 21, 17, 41, 6, 12, 33, 20, 4, 43, 21, 35, 19, 3, 50, 22, 38, 24, 50, 10, 19, 37]

cp's OEIS Frontend

A048984 As n runs through composite numbers, a(n) = number of nonprime d < n such that gcd(d,n) = 1.

Table of values

List of values

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

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

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