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.

A208556 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.

Table of values

n a(n)
1 9
2 81
3 225
4 1089
5 3969
6 16641
7 65025
8 263169
9 1046529
10 4198401
11 16769025
12 67125249
13 268402689
14 1073807361
15 4294836225
16 17180131329
17 68718952449
18 274878955521
19 1099509530625
20 4398050705409
21 17592177655809
22 70368760954881

List of values

[9, 81, 225, 1089, 3969, 16641, 65025, 263169, 1046529, 4198401, 16769025, 67125249, 268402689, 1073807361, 4294836225, 17180131329, 68718952449, 274878955521, 1099509530625, 4398050705409, 17592177655809, 70368760954881]