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 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 18 |
| 4 | 40 |
| 5 | 84 |
| 6 | 182 |
| 7 | 378 |
| 8 | 814 |
| 9 | 1686 |
| 10 | 3626 |
| 11 | 7506 |
| 12 | 16138 |
| 13 | 33402 |
| 14 | 71810 |
| 15 | 148626 |
| 16 | 319522 |
| 17 | 661314 |
| 18 | 1421714 |
| 19 | 2942514 |
| 20 | 6325906 |
| 21 | 13092690 |
| 22 | 28147058 |
| 23 | 58255794 |
| 24 | 125240050 |
| 25 | 259208562 |
| 26 | 557254322 |
| 27 | 1153345842 |
| 28 | 2479497394 |