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.

A217811 Number of alternating permutations on 2n letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).

Table of values

n a(n)
1 1
2 5
3 61
4 744
5 10329
6 157586
7 2581722
8 44710952
9 809508414

List of values

[1, 5, 61, 744, 10329, 157586, 2581722, 44710952, 809508414]