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.

A143878 Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric about main diagonal.

Table of values

n a(n)
0 1
1 2
2 5
3 17
4 92
5 581
6 4989
7 54250
8 776877
9 14503255
10 356467268
11 11553201879
12 495106836021

List of values

[1, 2, 5, 17, 92, 581, 4989, 54250, 776877, 14503255, 356467268, 11553201879, 495106836021]