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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.

A183981 1/4 the number of (n+1) X 5 binary arrays with all 2 X 2 subblock sums the same.

Table of values

n a(n)
1 15
2 17
3 20
4 26
5 36
6 56
7 92
8 164
9 300
10 572
11 1100
12 2156
13 4236
14 8396
15 16652
16 33164
17 66060
18 131852
19 263180
20 525836
21 1050636
22 2100236
23 4198412
24 8394764
25 16785420
26 33566732
27 67125260
28 134242316
29 268468236
30 536920076
31 1073807372
32 2147581964
33 4295098380

List of values

[15, 17, 20, 26, 36, 56, 92, 164, 300, 572, 1100, 2156, 4236, 8396, 16652, 33164, 66060, 131852, 263180, 525836, 1050636, 2100236, 4198412, 8394764, 16785420, 33566732, 67125260, 134242316, 268468236, 536920076, 1073807372, 2147581964, 4295098380]

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

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