A002472 - cp's OEIS frontend

A002472 Number of pairs x,y such that y-x=2, (x,n)=1, (y,n)=1 and 1 <= x <= n.

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

[1, 1, 1, 2, 3, 1, 5, 4, 3, 3, 9, 2, 11, 5, 3, 8, 15, 3, 17, 6, 5, 9, 21, 4, 15, 11, 9, 10, 27, 3, 29, 16, 9, 15, 15, 6, 35, 17, 11, 12, 39, 5, 41, 18, 9, 21, 45, 8, 35, 15, 15, 22, 51, 9, 27, 20, 17, 27, 57, 6, 59, 29, 15, 32, 33, 9, 65, 30, 21, 15, 69, 12, 71, 35, 15, 34, 45, 11, 77, 24, 27]

cp's OEIS Frontend

A002472 Number of pairs x,y such that y-x=2, (x,n)=1, (y,n)=1 and 1 <= x <= n.

Table of values

List of values

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

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

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