A085785 - cp's OEIS frontend

A085785 Start at (2n+1)/4 and iterate the map x -> x*ceiling(x); sequence gives number of steps for denominator to drop to 1 or 2; or -1 if this never happens.

n	a(n)
2	1
3	1
4	3
5	7
6	1
7	1
8	2
9	2
10	1
11	1
12	2
13	2
14	1
15	1
16	6
17	3
18	1
19	1
20	4
21	3
22	1
23	1
24	2
25	2
26	1
27	1
28	2
29	2
30	1
31	1
32	3
33	3
34	1
35	1
36	5
37	3
38	1
39	1
40	2
41	2
42	1
43	1
44	2
45	2
46	1
47	1
48	3
49	4
50	1
51	1
52	3
53	5
54	1
55	1
56	2
57	2
58	1
59	1
60	2
61	2
62	1
63	1
64	6
65	7
66	1
67	1
68	3
69	5
70	1
71	1
72	2
73	2
74	1
75	1
76	2
77	2
78	1
79	1
80	5
81	3
82	1
83	1
84	5
85	3
86	1
87	1
88	2
89	2
90	1
91	1
92	2
93	2
94	1
95	1
96	3
97	3
98	1
99	1
100	8
101	3
102	1
103	1
104	2
105	2
106	1

[1, 1, 3, 7, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 6, 3, 1, 1, 4, 3, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 3, 3, 1, 1, 5, 3, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 3, 4, 1, 1, 3, 5, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 6, 7, 1, 1, 3, 5, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 5, 3, 1, 1, 5, 3, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 3, 3, 1, 1, 8, 3, 1, 1, 2, 2, 1]

cp's OEIS Frontend

A085785 Start at (2n+1)/4 and iterate the map x -> x*ceiling(x); sequence gives number of steps for denominator to drop to 1 or 2; or -1 if this never happens.

Table of values

List of values

n	a(n)
2	1
3	1
4	3
5	7
6	1
7	1
8	2
9	2
10	1
11	1
12	2
13	2
14	1
15	1
16	6
17	3
18	1
19	1
20	4
21	3
22	1
23	1
24	2
25	2
26	1
27	1
28	2
29	2
30	1
31	1
32	3
33	3
34	1
35	1
36	5
37	3
38	1
39	1
40	2
41	2
42	1
43	1
44	2
45	2
46	1
47	1
48	3
49	4
50	1
51	1
52	3
53	5
54	1
55	1
56	2
57	2
58	1
59	1
60	2
61	2
62	1
63	1
64	6
65	7
66	1
67	1
68	3
69	5
70	1
71	1
72	2
73	2
74	1
75	1
76	2
77	2
78	1
79	1
80	5
81	3
82	1
83	1
84	5
85	3
86	1
87	1
88	2
89	2
90	1
91	1
92	2
93	2
94	1
95	1
96	3
97	3
98	1
99	1
100	8
101	3
102	1
103	1
104	2
105	2
106	1

n	a(n)
2	1
3	1
4	3
5	7
6	1
7	1
8	2
9	2
10	1
11	1
12	2
13	2
14	1
15	1
16	6
17	3
18	1
19	1
20	4
21	3
22	1
23	1
24	2
25	2
26	1
27	1
28	2
29	2
30	1
31	1
32	3
33	3
34	1
35	1
36	5
37	3
38	1
39	1
40	2
41	2
42	1
43	1
44	2
45	2
46	1
47	1
48	3
49	4
50	1
51	1
52	3
53	5
54	1
55	1
56	2
57	2
58	1
59	1
60	2
61	2
62	1
63	1
64	6
65	7
66	1
67	1
68	3
69	5
70	1
71	1
72	2
73	2
74	1
75	1
76	2
77	2
78	1
79	1
80	5
81	3
82	1
83	1
84	5
85	3
86	1
87	1
88	2
89	2
90	1
91	1
92	2
93	2
94	1
95	1
96	3
97	3
98	1
99	1
100	8
101	3
102	1
103	1
104	2
105	2
106	1

n	a(n)
2	1
3	1
4	3
5	7
6	1
7	1
8	2
9	2
10	1
11	1
12	2
13	2
14	1
15	1
16	6
17	3
18	1
19	1
20	4
21	3
22	1
23	1
24	2
25	2
26	1
27	1
28	2
29	2
30	1
31	1
32	3
33	3
34	1
35	1
36	5
37	3
38	1
39	1
40	2
41	2
42	1
43	1
44	2
45	2
46	1
47	1
48	3
49	4
50	1
51	1
52	3
53	5
54	1
55	1
56	2
57	2
58	1
59	1
60	2
61	2
62	1
63	1
64	6
65	7
66	1
67	1
68	3
69	5
70	1
71	1
72	2
73	2
74	1
75	1
76	2
77	2
78	1
79	1
80	5
81	3
82	1
83	1
84	5
85	3
86	1
87	1
88	2
89	2
90	1
91	1
92	2
93	2
94	1
95	1
96	3
97	3
98	1
99	1
100	8
101	3
102	1
103	1
104	2
105	2
106	1