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.

A054474 Number of walks on square lattice that start and end at origin after 2n steps, not touching origin at intermediate stages.

Table of values

n a(n)
0 1
1 4
2 20
3 176
4 1876
5 22064
6 275568
7 3584064
8 47995476
9 657037232
10 9150655216
11 129214858304
12 1845409805168
13 26606114089024
14 386679996988736
15 5658611409163008
16 83302885723872852
17 1232764004638179504
18 18327520881735288432
19 273595871825723062848

List of values

[1, 4, 20, 176, 1876, 22064, 275568, 3584064, 47995476, 657037232, 9150655216, 129214858304, 1845409805168, 26606114089024, 386679996988736, 5658611409163008, 83302885723872852, 1232764004638179504, 18327520881735288432, 273595871825723062848]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.