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.

A344605 Number of alternating patterns of length n, including pairs (x,x).

Table of values

n a(n)
0 1
1 1
2 3
3 6
4 22
5 102
6 562
7 3618
8 26586
9 219798
10 2018686
11 20393790
12 224750298
13 2683250082
14 34498833434
15 475237879950
16 6983085189454
17 109021986683046
18 1802213242949602
19 31447143854808378
20 577609702827987882
21 11139837273501641502
22 225075546284489412854

List of values

[1, 1, 3, 6, 22, 102, 562, 3618, 26586, 219798, 2018686, 20393790, 224750298, 2683250082, 34498833434, 475237879950, 6983085189454, 109021986683046, 1802213242949602, 31447143854808378, 577609702827987882, 11139837273501641502, 225075546284489412854]