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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.

A202972 Number of n X n 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.

Table of values

n a(n)
1 1
2 2
3 17
4 385
5 31380
6 8071997
7 6330398606
8 15305115754880
9 113359928263133320
10 2565928235760939767164
11 177686302889022383527488349
12 37653160193950657089306550224687
13 24413727008012244865702150476410950284

List of values

[1, 2, 17, 385, 31380, 8071997, 6330398606, 15305115754880, 113359928263133320, 2565928235760939767164, 177686302889022383527488349, 37653160193950657089306550224687, 24413727008012244865702150476410950284]

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

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