A087656 - cp's OEIS frontend

A087656 Let f be defined on the rationals by f(p/q) =(p+1)/(q+1)=p_{1}/q_{1} where (p_{1},q_{1})=1. Let f^k(p/q)=p_{k}/q_{k} where (p_{k},q_{k})=1. Sequence gives least k such that p_{k}-q_{k} = 1 starting at n.

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

[1, 2, 2, 4, 3, 6, 3, 4, 5, 10, 4, 12, 7, 6, 4, 16, 5, 18, 6, 8, 11, 22, 5, 8, 13, 6, 8, 28, 7, 30, 5, 12, 17, 10, 6, 36, 19, 14, 7, 40, 9, 42, 12, 8, 23, 46, 6, 12, 9, 18, 14, 52, 7, 14, 9, 20, 29, 58, 8, 60, 31, 10, 6, 16, 13, 66, 18, 24, 11, 70, 7, 72, 37, 10, 20, 16, 15, 78, 8, 8, 41, 82]

cp's OEIS Frontend

A087656 Let f be defined on the rationals by f(p/q) =(p+1)/(q+1)=p_{1}/q_{1} where (p_{1},q_{1})=1. Let f^k(p/q)=p_{k}/q_{k} where (p_{k},q_{k})=1. Sequence gives least k such that p_{k}-q_{k} = 1 starting at n.

Table of values

List of values

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

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

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