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.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 33 |
| 7 | 89 |
| 8 | 258 |
| 9 | 756 |
| 10 | 2279 |
| 11 | 6957 |
| 12 | 21592 |
| 13 | 67689 |
| 14 | 214451 |
| 15 | 684850 |
| 16 | 2203384 |
| 17 | 7133042 |
| 18 | 23222003 |
| 19 | 75971636 |
| 20 | 249646198 |
| 21 | 823597534 |
| 22 | 2726859943 |
| 23 | 9057797752 |
| 24 | 30176758016 |
| 25 | 100810029178 |
| 26 | 337614951216 |
| 27 | 1133292965615 |
| 28 | 3812333876764 |
| 29 | 12849946139206 |