A124676 - cp's OEIS frontend

A124676 a(n) = largest integer < n such that the positive integers <= a(n) and coprime to a(n) are also coprime to n.

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

[1, 2, 2, 4, 2, 6, 6, 6, 4, 10, 6, 12, 6, 3, 14, 16, 12, 18, 10, 6, 10, 22, 18, 20, 12, 24, 14, 28, 2, 30, 30, 9, 16, 5, 30, 36, 18, 12, 30, 40, 6, 42, 22, 30, 22, 46, 42, 42, 40, 15, 26, 52, 48, 10, 42, 18, 28, 58, 30, 60, 30, 42, 62, 10, 6, 66, 34, 21, 4, 70, 66, 72, 36, 60, 38, 7, 12]

cp's OEIS Frontend

A124676 a(n) = largest integer < n such that the positive integers <= a(n) and coprime to a(n) are also coprime to n.

Table of values

List of values

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

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

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