cp's OEIS Frontend

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.

A186474 Number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock commuting with each of its horizontal and vertical 2 X 2 subblock neighbors.

Table of values

n a(n)
1 256
2 205
3 1098
4 1251
5 4895
6 5955
7 20079
8 27101
9 84228
10 123227
11 354915
12 553287
13 1501107
14 2465976
15 6374253
16 10928793
17 27157017
18 48218637
19 116026140
20 211997451
21 496891083
22 929460999
23 2132220387
24 4065922560
25 9164874045
26 17754363633

List of values

[256, 205, 1098, 1251, 4895, 5955, 20079, 27101, 84228, 123227, 354915, 553287, 1501107, 2465976, 6374253, 10928793, 27157017, 48218637, 116026140, 211997451, 496891083, 929460999, 2132220387, 4065922560, 9164874045, 17754363633]

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

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