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.

A320334 Number of ways to group the first 2*n positive integers into n pairs (xi, yi) with xi < yi, and such that the n numbers (yi - xi) mod n are all different.

Table of values

n a(n)
0 1
1 1
2 0
3 3
4 12
5 25
6 0
7 475
8 5352
9 17157
10 0
11 896535
12 15083680
13 68879713
14 0

List of values

[1, 1, 0, 3, 12, 25, 0, 475, 5352, 17157, 0, 896535, 15083680, 68879713, 0]