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.

A233019 Number of n X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.

Table of values

n a(n)
1 1
2 15
3 849
4 179999
5 149128385
6 487651369463
7 6338787392715565
8 328918675019714663095
9 68332288847776936953486283
10 56955693489584720827393016043135

List of values

[1, 15, 849, 179999, 149128385, 487651369463, 6338787392715565, 328918675019714663095, 68332288847776936953486283, 56955693489584720827393016043135]

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

Content is available under The OEIS End-User License Agreement.