A085833 - cp's OEIS frontend

A085833 Start at (2n+1)/4 and iterate the map x -> x*ceiling(x); sequence gives values of n for which the denominators in the orbit go from 4 to 2, instead of dropping directly to 1.

n	a(n)
1	2
2	3
3	5
4	8
5	10
6	11
7	16
8	17
9	18
10	19
11	25
12	26
13	27
14	28
15	29
16	32
17	33
18	34
19	35
20	37
21	40
22	42
23	43
24	48
25	49
26	50
27	51
28	57
29	58
30	59
31	60
32	61
33	64
34	65
35	66
36	67
37	68
38	72
39	74
40	75
41	80
42	82
43	83
44	84
45	85
46	89
47	90
48	91
49	92
50	93
51	98
52	99
53	100
54	104
55	106
56	107
57	113
58	114
59	115
60	116
61	117
62	121
63	122
64	123
65	124
66	125
67	128
68	130

[2, 3, 5, 8, 10, 11, 16, 17, 18, 19, 25, 26, 27, 28, 29, 32, 33, 34, 35, 37, 40, 42, 43, 48, 49, 50, 51, 57, 58, 59, 60, 61, 64, 65, 66, 67, 68, 72, 74, 75, 80, 82, 83, 84, 85, 89, 90, 91, 92, 93, 98, 99, 100, 104, 106, 107, 113, 114, 115, 116, 117, 121, 122, 123, 124, 125, 128, 130]

cp's OEIS Frontend

A085833 Start at (2n+1)/4 and iterate the map x -> x*ceiling(x); sequence gives values of n for which the denominators in the orbit go from 4 to 2, instead of dropping directly to 1.

Table of values

List of values

n	a(n)
1	2
2	3
3	5
4	8
5	10
6	11
7	16
8	17
9	18
10	19
11	25
12	26
13	27
14	28
15	29
16	32
17	33
18	34
19	35
20	37
21	40
22	42
23	43
24	48
25	49
26	50
27	51
28	57
29	58
30	59
31	60
32	61
33	64
34	65
35	66
36	67
37	68
38	72
39	74
40	75
41	80
42	82
43	83
44	84
45	85
46	89
47	90
48	91
49	92
50	93
51	98
52	99
53	100
54	104
55	106
56	107
57	113
58	114
59	115
60	116
61	117
62	121
63	122
64	123
65	124
66	125
67	128
68	130

n	a(n)
1	2
2	3
3	5
4	8
5	10
6	11
7	16
8	17
9	18
10	19
11	25
12	26
13	27
14	28
15	29
16	32
17	33
18	34
19	35
20	37
21	40
22	42
23	43
24	48
25	49
26	50
27	51
28	57
29	58
30	59
31	60
32	61
33	64
34	65
35	66
36	67
37	68
38	72
39	74
40	75
41	80
42	82
43	83
44	84
45	85
46	89
47	90
48	91
49	92
50	93
51	98
52	99
53	100
54	104
55	106
56	107
57	113
58	114
59	115
60	116
61	117
62	121
63	122
64	123
65	124
66	125
67	128
68	130

n	a(n)
1	2
2	3
3	5
4	8
5	10
6	11
7	16
8	17
9	18
10	19
11	25
12	26
13	27
14	28
15	29
16	32
17	33
18	34
19	35
20	37
21	40
22	42
23	43
24	48
25	49
26	50
27	51
28	57
29	58
30	59
31	60
32	61
33	64
34	65
35	66
36	67
37	68
38	72
39	74
40	75
41	80
42	82
43	83
44	84
45	85
46	89
47	90
48	91
49	92
50	93
51	98
52	99
53	100
54	104
55	106
56	107
57	113
58	114
59	115
60	116
61	117
62	121
63	122
64	123
65	124
66	125
67	128
68	130