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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.

A208903 The sum over all bitstrings b of length n with at least two runs of the number of runs in b not immediately followed by a longer run.

Table of values

n a(n)
1 0
2 4
3 12
4 32
5 76
6 180
7 412
8 940
9 2108
10 4700
11 10364
12 22716
13 49404
14 106876
15 229884
16 492284
17 1049596
18 2229756
19 4720636
20 9964540
21 20975612
22 44046332
23 92282876
24 192950268
25 402669564
26 838885372
27 1744863228
28 3623927804
29 7516258300
30 15569354748
31 32212385788

List of values

[0, 4, 12, 32, 76, 180, 412, 940, 2108, 4700, 10364, 22716, 49404, 106876, 229884, 492284, 1049596, 2229756, 4720636, 9964540, 20975612, 44046332, 92282876, 192950268, 402669564, 838885372, 1744863228, 3623927804, 7516258300, 15569354748, 32212385788]

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

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