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.

A217821 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 61
4 1194
5 30945
6 970717
7 35033427
8 1408275466

List of values

[1, 5, 61, 1194, 30945, 970717, 35033427, 1408275466]