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.

A221287 Equals two maps: number of n X n binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 n X n array.

Table of values

n a(n)
1 1
2 4
3 92
4 9107
5 4983598
6 10344276279

List of values

[1, 4, 92, 9107, 4983598, 10344276279]

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

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