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.

A243634 Number of length n+2 0..n arrays with no three unequal elements in a row and new values 0..n introduced in 0..n order.

Table of values

n a(n)
1 4
2 9
3 21
4 51
5 127
6 324
7 844
8 2243
9 6073
10 16737
11 46905
12 133556
13 386062
14 1132107
15 3365627
16 10137559
17 30920943
18 95457178
19 298128278
20 941574417
21 3006040523
22 9697677885
23 31602993021
24 104001763258
25 345524136076
26 1158570129917

List of values

[4, 9, 21, 51, 127, 324, 844, 2243, 6073, 16737, 46905, 133556, 386062, 1132107, 3365627, 10137559, 30920943, 95457178, 298128278, 941574417, 3006040523, 9697677885, 31602993021, 104001763258, 345524136076, 1158570129917]