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.

A320168 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 mod xi) are all different.

Table of values

n a(n)
0 1
1 1
2 2
3 2
4 7
5 12
6 22
7 26
8 85
9 226
10 717
11 1695
12 5071
13 14275
14 47405
15 176747
16 638329
17 2166516

List of values

[1, 1, 2, 2, 7, 12, 22, 26, 85, 226, 717, 1695, 5071, 14275, 47405, 176747, 638329, 2166516]