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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.

A000013 Definition (1): Number of n-bead binary necklaces with beads of 2 colors where the colors may be swapped but turning over is not allowed.

Table of values

n a(n)
0 1
1 1
2 2
3 2
4 4
5 4
6 8
7 10
8 20
9 30
10 56
11 94
12 180
13 316
14 596
15 1096
16 2068
17 3856
18 7316
19 13798
20 26272
21 49940
22 95420
23 182362
24 349716
25 671092
26 1290872
27 2485534
28 4794088
29 9256396
30 17896832
31 34636834
32 67110932
33 130150588
34 252648992
35 490853416
36 954444608
37 1857283156
38 3616828364

List of values

[1, 1, 2, 2, 4, 4, 8, 10, 20, 30, 56, 94, 180, 316, 596, 1096, 2068, 3856, 7316, 13798, 26272, 49940, 95420, 182362, 349716, 671092, 1290872, 2485534, 4794088, 9256396, 17896832, 34636834, 67110932, 130150588, 252648992, 490853416, 954444608, 1857283156, 3616828364]

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

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