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.

A290280 Number of pairs of orthogonal (diagonal, antidiagonal) X-rays for all permutations of [n].

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 23
5 115
6 674
7 4718
8 37371
9 335435
10 3340116

List of values

[1, 1, 2, 6, 23, 115, 674, 4718, 37371, 335435, 3340116]