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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.

A274493 Number of bargraphs of semiperimeter n having no horizontal segments of length 1 (n>=2). By a horizontal segment of length 1 we mean a horizontal step that is not adjacent to any other horizontal step.

Table of values

n a(n)
2 0
3 1
4 2
5 3
6 6
7 13
8 27
9 57
10 123
11 267
12 584
13 1289
14 2864
15 6399
16 14373
17 32435
18 73498
19 167175
20 381551
21 873541
22 2005622
23 4616895
24 10653607
25 24638263
26 57097885
27 132575577
28 308378460
29 718506295
30 1676706422
31 3918515001
32 9170350093
33 21488961641
34 50417138776
35 118425429213
36 278476687643

List of values

[0, 1, 2, 3, 6, 13, 27, 57, 123, 267, 584, 1289, 2864, 6399, 14373, 32435, 73498, 167175, 381551, 873541, 2005622, 4616895, 10653607, 24638263, 57097885, 132575577, 308378460, 718506295, 1676706422, 3918515001, 9170350093, 21488961641, 50417138776, 118425429213, 278476687643]

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

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