A335870 - cp's OEIS frontend

A335870 a(n) is the least k > 0 such that T^k(n) = T^(2*k)(n) (where T^k denotes the k-th iterate of A006370, the Collatz map); a(n) = -1 if no such k exists.

n	a(n)
0	1
1	3
2	3
3	6
4	3
5	3
6	6
7	15
8	3
9	18
10	6
11	12
12	9
13	9
14	15
15	15
16	3
17	12
18	18
19	18
20	6
21	6
22	15
23	15
24	9
25	21
26	9
27	111
28	18
29	18
30	18
31	105
32	3
33	24
34	12
35	12
36	21
37	21
38	21
39	33
40	6
41	108
42	6
43	27
44	15
45	15
46	15
47	102
48	9
49	24
50	24
51	24
52	9
53	9
54	111
55	111
56	18
57	30
58	18
59	30
60	18
61	18
62	105
63	105
64	6
65	27
66	27
67	27
68	12

[1, 3, 3, 6, 3, 3, 6, 15, 3, 18, 6, 12, 9, 9, 15, 15, 3, 12, 18, 18, 6, 6, 15, 15, 9, 21, 9, 111, 18, 18, 18, 105, 3, 24, 12, 12, 21, 21, 21, 33, 6, 108, 6, 27, 15, 15, 15, 102, 9, 24, 24, 24, 9, 9, 111, 111, 18, 30, 18, 30, 18, 18, 105, 105, 6, 27, 27, 27, 12]

cp's OEIS Frontend

A335870 a(n) is the least k > 0 such that T^k(n) = T^(2*k)(n) (where T^k denotes the k-th iterate of A006370, the Collatz map); a(n) = -1 if no such k exists.

Table of values

List of values

n	a(n)
0	1
1	3
2	3
3	6
4	3
5	3
6	6
7	15
8	3
9	18
10	6
11	12
12	9
13	9
14	15
15	15
16	3
17	12
18	18
19	18
20	6
21	6
22	15
23	15
24	9
25	21
26	9
27	111
28	18
29	18
30	18
31	105
32	3
33	24
34	12
35	12
36	21
37	21
38	21
39	33
40	6
41	108
42	6
43	27
44	15
45	15
46	15
47	102
48	9
49	24
50	24
51	24
52	9
53	9
54	111
55	111
56	18
57	30
58	18
59	30
60	18
61	18
62	105
63	105
64	6
65	27
66	27
67	27
68	12

n	a(n)
0	1
1	3
2	3
3	6
4	3
5	3
6	6
7	15
8	3
9	18
10	6
11	12
12	9
13	9
14	15
15	15
16	3
17	12
18	18
19	18
20	6
21	6
22	15
23	15
24	9
25	21
26	9
27	111
28	18
29	18
30	18
31	105
32	3
33	24
34	12
35	12
36	21
37	21
38	21
39	33
40	6
41	108
42	6
43	27
44	15
45	15
46	15
47	102
48	9
49	24
50	24
51	24
52	9
53	9
54	111
55	111
56	18
57	30
58	18
59	30
60	18
61	18
62	105
63	105
64	6
65	27
66	27
67	27
68	12

n	a(n)
0	1
1	3
2	3
3	6
4	3
5	3
6	6
7	15
8	3
9	18
10	6
11	12
12	9
13	9
14	15
15	15
16	3
17	12
18	18
19	18
20	6
21	6
22	15
23	15
24	9
25	21
26	9
27	111
28	18
29	18
30	18
31	105
32	3
33	24
34	12
35	12
36	21
37	21
38	21
39	33
40	6
41	108
42	6
43	27
44	15
45	15
46	15
47	102
48	9
49	24
50	24
51	24
52	9
53	9
54	111
55	111
56	18
57	30
58	18
59	30
60	18
61	18
62	105
63	105
64	6
65	27
66	27
67	27
68	12