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.

A217801 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 12
3 106
4 1138
5 13734
6 179192
7 2471958
8 35557668

List of values

[1, 2, 12, 106, 1138, 13734, 179192, 2471958, 35557668]