A020651 - cp's OEIS frontend

A020651 Denominators in recursive bijection from positive integers to positive rationals (the bijection is f(1) = 1, f(2n) = f(n)+1, f(2n+1) = 1/(f(n)+1)).

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	2
7	3
8	1
9	4
10	3
11	4
12	2
13	5
14	3
15	5
16	1
17	5
18	4
19	5
20	3
21	7
22	4
23	7
24	2
25	7
26	5
27	7
28	3
29	8
30	5
31	8
32	1
33	6
34	5
35	6
36	4
37	9
38	5
39	9
40	3
41	10
42	7
43	10
44	4
45	11
46	7
47	11
48	2
49	9
50	7
51	9
52	5
53	12
54	7
55	12
56	3
57	11
58	8
59	11
60	5
61	13
62	8
63	13
64	1
65	7
66	6
67	7
68	5
69	11
70	6
71	11
72	4
73	13
74	9
75	13
76	5
77	14
78	9
79	14
80	3
81	13
82	10
83	13
84	7
85	17
86	10
87	17
88	4
89	15
90	11
91	15
92	7
93	18
94	11

[1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 4, 2, 5, 3, 5, 1, 5, 4, 5, 3, 7, 4, 7, 2, 7, 5, 7, 3, 8, 5, 8, 1, 6, 5, 6, 4, 9, 5, 9, 3, 10, 7, 10, 4, 11, 7, 11, 2, 9, 7, 9, 5, 12, 7, 12, 3, 11, 8, 11, 5, 13, 8, 13, 1, 7, 6, 7, 5, 11, 6, 11, 4, 13, 9, 13, 5, 14, 9, 14, 3, 13, 10, 13, 7, 17, 10, 17, 4, 15, 11, 15, 7, 18, 11]

cp's OEIS Frontend

A020651 Denominators in recursive bijection from positive integers to positive rationals (the bijection is f(1) = 1, f(2n) = f(n)+1, f(2n+1) = 1/(f(n)+1)).

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	2
7	3
8	1
9	4
10	3
11	4
12	2
13	5
14	3
15	5
16	1
17	5
18	4
19	5
20	3
21	7
22	4
23	7
24	2
25	7
26	5
27	7
28	3
29	8
30	5
31	8
32	1
33	6
34	5
35	6
36	4
37	9
38	5
39	9
40	3
41	10
42	7
43	10
44	4
45	11
46	7
47	11
48	2
49	9
50	7
51	9
52	5
53	12
54	7
55	12
56	3
57	11
58	8
59	11
60	5
61	13
62	8
63	13
64	1
65	7
66	6
67	7
68	5
69	11
70	6
71	11
72	4
73	13
74	9
75	13
76	5
77	14
78	9
79	14
80	3
81	13
82	10
83	13
84	7
85	17
86	10
87	17
88	4
89	15
90	11
91	15
92	7
93	18
94	11

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	2
7	3
8	1
9	4
10	3
11	4
12	2
13	5
14	3
15	5
16	1
17	5
18	4
19	5
20	3
21	7
22	4
23	7
24	2
25	7
26	5
27	7
28	3
29	8
30	5
31	8
32	1
33	6
34	5
35	6
36	4
37	9
38	5
39	9
40	3
41	10
42	7
43	10
44	4
45	11
46	7
47	11
48	2
49	9
50	7
51	9
52	5
53	12
54	7
55	12
56	3
57	11
58	8
59	11
60	5
61	13
62	8
63	13
64	1
65	7
66	6
67	7
68	5
69	11
70	6
71	11
72	4
73	13
74	9
75	13
76	5
77	14
78	9
79	14
80	3
81	13
82	10
83	13
84	7
85	17
86	10
87	17
88	4
89	15
90	11
91	15
92	7
93	18
94	11

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	2
7	3
8	1
9	4
10	3
11	4
12	2
13	5
14	3
15	5
16	1
17	5
18	4
19	5
20	3
21	7
22	4
23	7
24	2
25	7
26	5
27	7
28	3
29	8
30	5
31	8
32	1
33	6
34	5
35	6
36	4
37	9
38	5
39	9
40	3
41	10
42	7
43	10
44	4
45	11
46	7
47	11
48	2
49	9
50	7
51	9
52	5
53	12
54	7
55	12
56	3
57	11
58	8
59	11
60	5
61	13
62	8
63	13
64	1
65	7
66	6
67	7
68	5
69	11
70	6
71	11
72	4
73	13
74	9
75	13
76	5
77	14
78	9
79	14
80	3
81	13
82	10
83	13
84	7
85	17
86	10
87	17
88	4
89	15
90	11
91	15
92	7
93	18
94	11