A078420 - cp's OEIS frontend

A078420 Numbers n such that h(n) = 3 h(n-1) where h(n) is the length of the sequence {n, f(n), f(f(n)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)

n	a(n)
1	105
2	548
3	683
4	1508
5	3652
6	4278
7	4295
8	8145
9	8150
10	9417
11	9419
12	18247
13	18287
14	18370
15	18433
16	18586
17	18695
18	18706
19	18742
20	18945
21	22024
22	22140
23	22311
24	22324
25	22708
26	22714
27	25336
28	25681
29	25771
30	25777
31	25785
32	25814
33	44545
34	44593
35	46505
36	46847

[105, 548, 683, 1508, 3652, 4278, 4295, 8145, 8150, 9417, 9419, 18247, 18287, 18370, 18433, 18586, 18695, 18706, 18742, 18945, 22024, 22140, 22311, 22324, 22708, 22714, 25336, 25681, 25771, 25777, 25785, 25814, 44545, 44593, 46505, 46847]

cp's OEIS Frontend

A078420 Numbers n such that h(n) = 3 h(n-1) where h(n) is the length of the sequence {n, f(n), f(f(n)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)

Table of values

List of values