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.

A198180 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Table of values

n a(n)
1 1
2 3
3 9
4 25
5 77
6 148
7 395
8 866
9 2346
10 5663
11 14065
12 34309
13 84252
14 208413
15 513352
16 1266410
17 3117377
18 7679699
19 18927327
20 46639092
21 114949605
22 283220762
23 697929906
24 1719783577
25 4237987789
26 10443340285
27 25734497336
28 63415169957
29 156267786924

List of values

[1, 3, 9, 25, 77, 148, 395, 866, 2346, 5663, 14065, 34309, 84252, 208413, 513352, 1266410, 3117377, 7679699, 18927327, 46639092, 114949605, 283220762, 697929906, 1719783577, 4237987789, 10443340285, 25734497336, 63415169957, 156267786924]

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

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