A057475 - cp's OEIS frontend

A057475 Number of k, 1 <= k <= n, such that gcd(n,k) = gcd(n+1,k) = 1.

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

[1, 1, 1, 2, 1, 2, 3, 3, 2, 4, 3, 4, 5, 3, 4, 8, 5, 6, 7, 5, 5, 10, 7, 7, 9, 8, 8, 12, 7, 8, 15, 10, 9, 11, 8, 12, 17, 11, 9, 16, 11, 12, 19, 11, 11, 22, 15, 14, 17, 13, 15, 24, 17, 14, 17, 15, 17, 28, 15, 16, 29, 17, 18, 24, 15, 20, 31, 21, 15, 24, 23, 24, 35, 19, 19, 28, 18, 24, 31, 22]

cp's OEIS Frontend

A057475 Number of k, 1 <= k <= n, such that gcd(n,k) = gcd(n+1,k) = 1.

Table of values

List of values

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

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

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