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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.

A204709 Number of (n+1) X 5 0..1 arrays with the permanents of all 2 X 2 subblocks equal and nonzero.

Table of values

n a(n)
1 49
2 209
3 833
4 3473
5 14145
6 58449
7 239425
8 986129
9 4047681
10 16650449
11 68397889
12 281218705
13 1155579713
14 4750209361
15 19522035521
16 80241997073
17 329789811521
18 1355498530257
19 5571139502913
20 22898117877649
21 94112790021953

List of values

[49, 209, 833, 3473, 14145, 58449, 239425, 986129, 4047681, 16650449, 68397889, 281218705, 1155579713, 4750209361, 19522035521, 80241997073, 329789811521, 1355498530257, 5571139502913, 22898117877649, 94112790021953]

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

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