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.

A220581 Equals one maps: number of 3Xn binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 3Xn array.

Table of values

n a(n)
1 1
2 32
3 91
4 1441
5 8334
6 64497
7 436288
8 3036588
9 21023792
10 146254012
11 1011489196
12 7016643627
13 48603225482
14 336693889957
15 2332461879768
16 16156948253940
17 111913294295697
18 775187951935208
19 5369332881497134
20 37190288381188178

List of values

[1, 32, 91, 1441, 8334, 64497, 436288, 3036588, 21023792, 146254012, 1011489196, 7016643627, 48603225482, 336693889957, 2332461879768, 16156948253940, 111913294295697, 775187951935208, 5369332881497134, 37190288381188178]

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

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