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.

A143873 Number of ways of placing kings with no more than 1 mutual attack on an n X n chessboard symmetric about both diagonal and antidiagonal.

Table of values

n a(n)
0 1
1 2
2 3
3 5
4 8
5 21
6 53
7 158
8 503
9 2181
10 9658
11 53517
12 313683
13 2389270

List of values

[1, 2, 3, 5, 8, 21, 53, 158, 503, 2181, 9658, 53517, 313683, 2389270]