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.

A207840 Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 1 1 vertically.

Table of values

n a(n)
1 6
2 36
3 72
4 240
5 704
6 2080
7 6216
8 18496
9 55000
10 163760
11 487296
12 1450192
13 4315896
14 12844160
15 38224536
16 113757504
17 338545344
18 1007520656
19 2998410360
20 8923354336
21 26556156776
22 79031879392
23 235201123584
24 699965244000
25 2083116504872

List of values

[6, 36, 72, 240, 704, 2080, 6216, 18496, 55000, 163760, 487296, 1450192, 4315896, 12844160, 38224536, 113757504, 338545344, 1007520656, 2998410360, 8923354336, 26556156776, 79031879392, 235201123584, 699965244000, 2083116504872]

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

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