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.

A207027 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

Table of values

n a(n)
1 8
2 64
3 168
4 558
5 1586
6 3726
7 9450
8 21318
9 47518
10 104470
11 220531
12 464202
13 957412
14 1949906
15 3940218
16 7868976
17 15610980
18 30742563
19 60142488
20 117047084
21 226575095
22 436635184
23 837955970
24 1601924662
25 3051891570
26 5795441060
27 10972726928

List of values

[8, 64, 168, 558, 1586, 3726, 9450, 21318, 47518, 104470, 220531, 464202, 957412, 1949906, 3940218, 7868976, 15610980, 30742563, 60142488, 117047084, 226575095, 436635184, 837955970, 1601924662, 3051891570, 5795441060, 10972726928]