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.

A295209 Number of n X 4 0..1 arrays with each 1 horizontally or vertically adjacent to 2 or 3 1's.

Table of values

n a(n)
1 1
2 7
3 27
4 147
5 916
6 4938
7 27208
8 152236
9 848992
10 4746938
11 26555583
12 148468255
13 830063597
14 4640855585
15 25946470239
16 145065530889
17 811058197498
18 4534601269690
19 25352811924120
20 141746752099136
21 792501412285360

List of values

[1, 7, 27, 147, 916, 4938, 27208, 152236, 848992, 4746938, 26555583, 148468255, 830063597, 4640855585, 25946470239, 145065530889, 811058197498, 4534601269690, 25352811924120, 141746752099136, 792501412285360]

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

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