A126241 - cp's OEIS frontend

A126241 Dropping times in the 3n+1 problem (or the Collatz problem). Let T(n):=n/2 if n is even, (3n+1)/2 otherwise (A014682). Let a(n) be the smallest integer k such that T^(k)(n) where T^(k) is the k-th iterate, or infinity otherwise; a(n) is called the dropping time of n.

n	a(n)
1	0
2	1
3	4
4	1
5	2
6	1
7	7
8	1
9	2
10	1
11	5
12	1
13	2
14	1
15	7
16	1
17	2
18	1
19	4
20	1
21	2
22	1
23	5
24	1
25	2
26	1
27	59
28	1
29	2
30	1
31	56
32	1
33	2
34	1
35	4
36	1
37	2
38	1
39	8
40	1
41	2
42	1
43	5
44	1
45	2
46	1
47	54
48	1
49	2
50	1
51	4
52	1
53	2
54	1
55	5
56	1
57	2
58	1
59	7
60	1
61	2
62	1
63	54
64	1
65	2
66	1
67	4
68	1
69	2
70	1
71	51
72	1
73	2
74	1
75	5
76	1
77	2
78	1
79	8
80	1
81	2
82	1
83	4
84	1
85	2
86	1
87	5
88	1
89	2
90	1
91	45
92	1
93	2
94	1
95	8
96	1
97	2
98	1
99	4

[0, 1, 4, 1, 2, 1, 7, 1, 2, 1, 5, 1, 2, 1, 7, 1, 2, 1, 4, 1, 2, 1, 5, 1, 2, 1, 59, 1, 2, 1, 56, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 5, 1, 2, 1, 54, 1, 2, 1, 4, 1, 2, 1, 5, 1, 2, 1, 7, 1, 2, 1, 54, 1, 2, 1, 4, 1, 2, 1, 51, 1, 2, 1, 5, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 5, 1, 2, 1, 45, 1, 2, 1, 8, 1, 2, 1, 4]

cp's OEIS Frontend

A126241 Dropping times in the 3n+1 problem (or the Collatz problem). Let T(n):=n/2 if n is even, (3n+1)/2 otherwise (A014682). Let a(n) be the smallest integer k such that T^(k)(n) where T^(k) is the k-th iterate, or infinity otherwise; a(n) is called the dropping time of n.

Table of values

List of values

n	a(n)
1	0
2	1
3	4
4	1
5	2
6	1
7	7
8	1
9	2
10	1
11	5
12	1
13	2
14	1
15	7
16	1
17	2
18	1
19	4
20	1
21	2
22	1
23	5
24	1
25	2
26	1
27	59
28	1
29	2
30	1
31	56
32	1
33	2
34	1
35	4
36	1
37	2
38	1
39	8
40	1
41	2
42	1
43	5
44	1
45	2
46	1
47	54
48	1
49	2
50	1
51	4
52	1
53	2
54	1
55	5
56	1
57	2
58	1
59	7
60	1
61	2
62	1
63	54
64	1
65	2
66	1
67	4
68	1
69	2
70	1
71	51
72	1
73	2
74	1
75	5
76	1
77	2
78	1
79	8
80	1
81	2
82	1
83	4
84	1
85	2
86	1
87	5
88	1
89	2
90	1
91	45
92	1
93	2
94	1
95	8
96	1
97	2
98	1
99	4

n	a(n)
1	0
2	1
3	4
4	1
5	2
6	1
7	7
8	1
9	2
10	1
11	5
12	1
13	2
14	1
15	7
16	1
17	2
18	1
19	4
20	1
21	2
22	1
23	5
24	1
25	2
26	1
27	59
28	1
29	2
30	1
31	56
32	1
33	2
34	1
35	4
36	1
37	2
38	1
39	8
40	1
41	2
42	1
43	5
44	1
45	2
46	1
47	54
48	1
49	2
50	1
51	4
52	1
53	2
54	1
55	5
56	1
57	2
58	1
59	7
60	1
61	2
62	1
63	54
64	1
65	2
66	1
67	4
68	1
69	2
70	1
71	51
72	1
73	2
74	1
75	5
76	1
77	2
78	1
79	8
80	1
81	2
82	1
83	4
84	1
85	2
86	1
87	5
88	1
89	2
90	1
91	45
92	1
93	2
94	1
95	8
96	1
97	2
98	1
99	4

n	a(n)
1	0
2	1
3	4
4	1
5	2
6	1
7	7
8	1
9	2
10	1
11	5
12	1
13	2
14	1
15	7
16	1
17	2
18	1
19	4
20	1
21	2
22	1
23	5
24	1
25	2
26	1
27	59
28	1
29	2
30	1
31	56
32	1
33	2
34	1
35	4
36	1
37	2
38	1
39	8
40	1
41	2
42	1
43	5
44	1
45	2
46	1
47	54
48	1
49	2
50	1
51	4
52	1
53	2
54	1
55	5
56	1
57	2
58	1
59	7
60	1
61	2
62	1
63	54
64	1
65	2
66	1
67	4
68	1
69	2
70	1
71	51
72	1
73	2
74	1
75	5
76	1
77	2
78	1
79	8
80	1
81	2
82	1
83	4
84	1
85	2
86	1
87	5
88	1
89	2
90	1
91	45
92	1
93	2
94	1
95	8
96	1
97	2
98	1
99	4