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.

A118997 Number of real n X n symmetric (+1,-1) matrices with negative determinant.

Table of values

n a(n)
1 1
2 4
3 16
4 80
5 8448
6 907904
7 81949952
8 13480664064
9 12792558313472
10 18963201072750592

List of values

[1, 4, 16, 80, 8448, 907904, 81949952, 13480664064, 12792558313472, 18963201072750592]