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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A221474 Number of families of numbers requiring n iterations of the Collatz (3x+1) function to reach 1.

Table of values

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

List of values

[1, 0, 0, 0, 0, 1, 0, 2, 0, 2, 0, 2, 2, 3, 3, 4, 4, 5, 4, 6, 5, 6, 5, 7, 6, 7, 7, 8, 7, 9, 8, 9, 9, 10, 10, 11, 10, 11, 11, 12, 11, 13, 12, 13, 13, 14, 14, 15, 14, 16, 15, 16, 16, 17, 17, 18, 17, 18, 18, 19, 19, 20, 19, 21, 20, 22, 21, 23, 22, 24]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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