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.

A217819 Number of alternating permutations on 2n letters that avoid a certain pattern of length 5 (see Lewis, 2012, Appendix, for precise definition).

Table of values

n a(n)
1 1
2 5
3 56
4 1004
5 24336
6 727807
7 25433281
8 1002714053

List of values

[1, 5, 56, 1004, 24336, 727807, 25433281, 1002714053]