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.

A217807 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 4
3 29
4 292
5 3620
6 51866
7 827415
8 14350467
9 266218320

List of values

[1, 4, 29, 292, 3620, 51866, 827415, 14350467, 266218320]