A067992 - cp's OEIS frontend

A067992 a(0)=1 and, for n > 0, a(n) is the smallest positive integer such that the ratios min(a(k)/a(k-1), a(k-1)/a(k)) for 0 < k <= n are all distinct.

n	a(n)
0	1
1	1
2	2
3	3
4	1
5	4
6	3
7	5
8	1
9	6
10	5
11	2
12	7
13	1
14	8
15	3
16	7
17	4
18	5
19	7
20	6
21	11
22	1
23	9
24	2
25	11
26	3
27	10
28	1
29	12
30	5
31	8
32	7
33	9
34	4
35	11
36	5
37	9
38	8
39	11
40	7
41	10
42	9
43	11
44	10
45	13
46	1
47	14
48	3
49	13
50	2
51	15
52	1
53	16
54	3
55	17
56	1
57	18
58	5
59	13
60	4
61	15
62	7
63	12
64	11
65	13
66	6
67	17
68	2
69	19
70	1
71	20
72	3
73	19
74	4
75	17
76	5
77	14
78	9
79	13
80	7
81	16
82	5
83	19
84	6
85	23
86	1
87	21
88	2

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

cp's OEIS Frontend

A067992 a(0)=1 and, for n > 0, a(n) is the smallest positive integer such that the ratios min(a(k)/a(k-1), a(k-1)/a(k)) for 0 < k <= n are all distinct.

Table of values

List of values

n	a(n)
0	1
1	1
2	2
3	3
4	1
5	4
6	3
7	5
8	1
9	6
10	5
11	2
12	7
13	1
14	8
15	3
16	7
17	4
18	5
19	7
20	6
21	11
22	1
23	9
24	2
25	11
26	3
27	10
28	1
29	12
30	5
31	8
32	7
33	9
34	4
35	11
36	5
37	9
38	8
39	11
40	7
41	10
42	9
43	11
44	10
45	13
46	1
47	14
48	3
49	13
50	2
51	15
52	1
53	16
54	3
55	17
56	1
57	18
58	5
59	13
60	4
61	15
62	7
63	12
64	11
65	13
66	6
67	17
68	2
69	19
70	1
71	20
72	3
73	19
74	4
75	17
76	5
77	14
78	9
79	13
80	7
81	16
82	5
83	19
84	6
85	23
86	1
87	21
88	2

n	a(n)
0	1
1	1
2	2
3	3
4	1
5	4
6	3
7	5
8	1
9	6
10	5
11	2
12	7
13	1
14	8
15	3
16	7
17	4
18	5
19	7
20	6
21	11
22	1
23	9
24	2
25	11
26	3
27	10
28	1
29	12
30	5
31	8
32	7
33	9
34	4
35	11
36	5
37	9
38	8
39	11
40	7
41	10
42	9
43	11
44	10
45	13
46	1
47	14
48	3
49	13
50	2
51	15
52	1
53	16
54	3
55	17
56	1
57	18
58	5
59	13
60	4
61	15
62	7
63	12
64	11
65	13
66	6
67	17
68	2
69	19
70	1
71	20
72	3
73	19
74	4
75	17
76	5
77	14
78	9
79	13
80	7
81	16
82	5
83	19
84	6
85	23
86	1
87	21
88	2

n	a(n)
0	1
1	1
2	2
3	3
4	1
5	4
6	3
7	5
8	1
9	6
10	5
11	2
12	7
13	1
14	8
15	3
16	7
17	4
18	5
19	7
20	6
21	11
22	1
23	9
24	2
25	11
26	3
27	10
28	1
29	12
30	5
31	8
32	7
33	9
34	4
35	11
36	5
37	9
38	8
39	11
40	7
41	10
42	9
43	11
44	10
45	13
46	1
47	14
48	3
49	13
50	2
51	15
52	1
53	16
54	3
55	17
56	1
57	18
58	5
59	13
60	4
61	15
62	7
63	12
64	11
65	13
66	6
67	17
68	2
69	19
70	1
71	20
72	3
73	19
74	4
75	17
76	5
77	14
78	9
79	13
80	7
81	16
82	5
83	19
84	6
85	23
86	1
87	21
88	2