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.

A217804 Number of alternating permutations on 2n+1 letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).

Table of values

n a(n)
0 1
1 2
2 16
3 168
4 2072
5 28298
6 414472
7 6387436
8 102316000

List of values

[1, 2, 16, 168, 2072, 28298, 414472, 6387436, 102316000]