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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.

A122742 Numbers of polypentagons with two connected internal vertices (see Cyvin et al. for precise definition).

Table of values

n a(n)
4 0
5 0
6 1
7 3
8 6
9 16
10 34
11 80
12 172
13 384
14 824
15 1792
16 3824
17 8192
18 17376
19 36864
20 77760
21 163840
22 343936
23 720896
24 1507072
25 3145728
26 6553088
27 13631488
28 28310528
29 58720256
30 121632768
31 251658240
32 520089600
33 1073741824
34 2214584320
35 4563402752
36 9395224576
37 19327352832
38 39728414720
39 81604378624

List of values

[0, 0, 1, 3, 6, 16, 34, 80, 172, 384, 824, 1792, 3824, 8192, 17376, 36864, 77760, 163840, 343936, 720896, 1507072, 3145728, 6553088, 13631488, 28310528, 58720256, 121632768, 251658240, 520089600, 1073741824, 2214584320, 4563402752, 9395224576, 19327352832, 39728414720, 81604378624]

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

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