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.

A183519 Number of nX2 0..2 arrays with each element equal to either the sum mod 3 of its horizontal and vertical neighbors or the sum mod 3 of its diagonal and antidiagonal neighbors.

Table of values

n a(n)
1 3
2 9
3 31
4 95
5 309
6 911
7 2803
8 8673
9 26619
10 81959
11 252477
12 777327
13 2393627
14 7371657
15 22698115
16 69895583
17 215235669
18 662786215
19 2040959827
20 6284869089
21 19353386043
22 59596135287
23 183518286189
24 565119695167
25 1740209766219
26 5358741068409

List of values

[3, 9, 31, 95, 309, 911, 2803, 8673, 26619, 81959, 252477, 777327, 2393627, 7371657, 22698115, 69895583, 215235669, 662786215, 2040959827, 6284869089, 19353386043, 59596135287, 183518286189, 565119695167, 1740209766219, 5358741068409]

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

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