A070554 - cp's OEIS frontend

A070554 Number of positive integers, k, where k <= 2n+1 and gcd(k, 2n+1) = gcd(k+1, 2n+1) = 1.

n	a(n)
0	1
1	1
2	3
3	5
4	3
5	9
6	11
7	3
8	15
9	17
10	5
11	21
12	15
13	9
14	27
15	29
16	9
17	15
18	35
19	11
20	39
21	41
22	9
23	45
24	35
25	15
26	51
27	27
28	17
29	57
30	59
31	15
32	33
33	65
34	21
35	69
36	71
37	15
38	45
39	77
40	27
41	81
42	45
43	27
44	87
45	55
46	29
47	51
48	95
49	27
50	99
51	101
52	15
53	105
54	107
55	35
56	111
57	63
58	33
59	75
60	99
61	39
62	75
63	125
64	41
65	129
66	85
67	27
68	135
69	137

[1, 1, 3, 5, 3, 9, 11, 3, 15, 17, 5, 21, 15, 9, 27, 29, 9, 15, 35, 11, 39, 41, 9, 45, 35, 15, 51, 27, 17, 57, 59, 15, 33, 65, 21, 69, 71, 15, 45, 77, 27, 81, 45, 27, 87, 55, 29, 51, 95, 27, 99, 101, 15, 105, 107, 35, 111, 63, 33, 75, 99, 39, 75, 125, 41, 129, 85, 27, 135, 137]

cp's OEIS Frontend

A070554 Number of positive integers, k, where k <= 2n+1 and gcd(k, 2n+1) = gcd(k+1, 2n+1) = 1.

Table of values

List of values

n	a(n)
0	1
1	1
2	3
3	5
4	3
5	9
6	11
7	3
8	15
9	17
10	5
11	21
12	15
13	9
14	27
15	29
16	9
17	15
18	35
19	11
20	39
21	41
22	9
23	45
24	35
25	15
26	51
27	27
28	17
29	57
30	59
31	15
32	33
33	65
34	21
35	69
36	71
37	15
38	45
39	77
40	27
41	81
42	45
43	27
44	87
45	55
46	29
47	51
48	95
49	27
50	99
51	101
52	15
53	105
54	107
55	35
56	111
57	63
58	33
59	75
60	99
61	39
62	75
63	125
64	41
65	129
66	85
67	27
68	135
69	137

n	a(n)
0	1
1	1
2	3
3	5
4	3
5	9
6	11
7	3
8	15
9	17
10	5
11	21
12	15
13	9
14	27
15	29
16	9
17	15
18	35
19	11
20	39
21	41
22	9
23	45
24	35
25	15
26	51
27	27
28	17
29	57
30	59
31	15
32	33
33	65
34	21
35	69
36	71
37	15
38	45
39	77
40	27
41	81
42	45
43	27
44	87
45	55
46	29
47	51
48	95
49	27
50	99
51	101
52	15
53	105
54	107
55	35
56	111
57	63
58	33
59	75
60	99
61	39
62	75
63	125
64	41
65	129
66	85
67	27
68	135
69	137

n	a(n)
0	1
1	1
2	3
3	5
4	3
5	9
6	11
7	3
8	15
9	17
10	5
11	21
12	15
13	9
14	27
15	29
16	9
17	15
18	35
19	11
20	39
21	41
22	9
23	45
24	35
25	15
26	51
27	27
28	17
29	57
30	59
31	15
32	33
33	65
34	21
35	69
36	71
37	15
38	45
39	77
40	27
41	81
42	45
43	27
44	87
45	55
46	29
47	51
48	95
49	27
50	99
51	101
52	15
53	105
54	107
55	35
56	111
57	63
58	33
59	75
60	99
61	39
62	75
63	125
64	41
65	129
66	85
67	27
68	135
69	137