A006666 - cp's OEIS frontend

A006666 Number of halving steps to reach 1 in '3x+1' problem, or -1 if this never happens.

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

[0, 1, 5, 2, 4, 6, 11, 3, 13, 5, 10, 7, 7, 12, 12, 4, 9, 14, 14, 6, 6, 11, 11, 8, 16, 8, 70, 13, 13, 13, 67, 5, 18, 10, 10, 15, 15, 15, 23, 7, 69, 7, 20, 12, 12, 12, 66, 9, 17, 17, 17, 9, 9, 71, 71, 14, 22, 14, 22, 14, 14, 68, 68, 6, 19, 19, 19, 11, 11, 11, 65, 16, 73, 16, 11, 16]

cp's OEIS Frontend

A006666 Number of halving steps to reach 1 in '3x+1' problem, or -1 if this never happens.

Table of values

List of values

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

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

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