cp's OEIS Frontend

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.

A089645 Penny Flipping, or Flipping Coins: Given a stack of n coins, flip the top coin, then the stack of the top two coins, then the stack of the top three etc... starting again with the top coin after flipping all n coins. A flip of m coins reverses their order and inverts their state. This is the number of flips required to restore the stack to its original configuration.

Table of values

n a(n)
1 2
2 3
3 9
4 11
5 24
6 35
7 28
8 31
9 80
10 60
11 121
12 119
13 116
14 195
15 75
16 79
17 204
18 323
19 228
20 199
21 146
22 264
23 529
24 504
25 200
26 675
27 540
28 251
29 840
30 899
31 186
32 191
33 1088
34 748
35 1225
36 324
37 740
38 1140
39 1521
40 1079
41 1680
42 336
43 1204
44 484
45 540
46 460
47 1692
48 1151
49 734
50 2499

List of values

[2, 3, 9, 11, 24, 35, 28, 31, 80, 60, 121, 119, 116, 195, 75, 79, 204, 323, 228, 199, 146, 264, 529, 504, 200, 675, 540, 251, 840, 899, 186, 191, 1088, 748, 1225, 324, 740, 1140, 1521, 1079, 1680, 336, 1204, 484, 540, 460, 1692, 1151, 734, 2499]

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

Content is available under The OEIS End-User License Agreement.