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.

A260154 Number of square lattice walks of length 2n starting and ending at (0,0) and avoiding the West quadrant {(i,j): i < -|j|}.

Table of values

n a(n)
0 1
1 3
2 22
3 209
4 2256
5 26296
6 322696
7 4109131
8 53802868
9 719967204
10 9804170810
11 135438150718
12 1893565055948
13 26744778067560
14 381061505993160
15 5470780479977505
16 79066952734823832
17 1149467155656304276
18 16798622641884084940
19 246654934301978877376

List of values

[1, 3, 22, 209, 2256, 26296, 322696, 4109131, 53802868, 719967204, 9804170810, 135438150718, 1893565055948, 26744778067560, 381061505993160, 5470780479977505, 79066952734823832, 1149467155656304276, 16798622641884084940, 246654934301978877376]

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

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