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.

A221519 Number of 0..3 arrays of length n with each element differing from at least one neighbor by 2 or more.

Table of values

n a(n)
1 0
2 6
3 10
4 36
5 94
6 274
7 768
8 2182
9 6170
10 17476
11 49470
12 140066
13 396544
14 1122694
15 3178538
16 8999012
17 25477790
18 72132146
19 204218880
20 578179846
21 1636929594
22 4634437764
23 13120914558
24 37147634242
25 105171535360
26 297759253766

List of values

[0, 6, 10, 36, 94, 274, 768, 2182, 6170, 17476, 49470, 140066, 396544, 1122694, 3178538, 8999012, 25477790, 72132146, 204218880, 578179846, 1636929594, 4634437764, 13120914558, 37147634242, 105171535360, 297759253766]