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.

A284428 Number of all self-avoiding planar walks of length j (0<=j<=n) starting at (0,0), ending at (n-j,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal.

Table of values

n a(n)
0 1
1 0
2 1
3 1
4 2
5 1
6 5
7 5
8 13
9 15
10 40
11 44
12 123
13 156
14 402
15 536
16 1361
17 1857
18 4689
19 6681
20 16536
21 24286
22 59400
23 89131
24 216114
25 331324
26 796029
27 1243168
28 2963859
29 4700410
30 11133792
31 17901901
32 42155014
33 68618679
34 160736012
35 264497624
36 616693942
37 1024713750
38 2379184108

List of values

[1, 0, 1, 1, 2, 1, 5, 5, 13, 15, 40, 44, 123, 156, 402, 536, 1361, 1857, 4689, 6681, 16536, 24286, 59400, 89131, 216114, 331324, 796029, 1243168, 2963859, 4700410, 11133792, 17901901, 42155014, 68618679, 160736012, 264497624, 616693942, 1024713750, 2379184108]

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

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