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.

A203536 Number of nX2 0..2 arrays with every element neighboring horizontally or vertically both a 0 and a 1.

Table of values

n a(n)
1 0
2 4
3 4
4 16
5 64
6 196
7 676
8 2304
9 7744
10 26244
11 88804
12 300304
13 1016064
14 3437316
15 11628100
16 39337984
17 133079296
18 450203524
19 1523028676
20 5152368400
21 17430336576
22 58966408900
23 199481929956
24 674842534144
25 2282975946304
26 7723252297476

List of values

[0, 4, 4, 16, 64, 196, 676, 2304, 7744, 26244, 88804, 300304, 1016064, 3437316, 11628100, 39337984, 133079296, 450203524, 1523028676, 5152368400, 17430336576, 58966408900, 199481929956, 674842534144, 2282975946304, 7723252297476]

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

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