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 | 10 |
| 3 | 33 |
| 4 | 108 |
| 5 | 352 |
| 6 | 1145 |
| 7 | 3721 |
| 8 | 12087 |
| 9 | 39254 |
| 10 | 127469 |
| 11 | 413908 |
| 12 | 1343980 |
| 13 | 4363921 |
| 14 | 14169633 |
| 15 | 46008619 |
| 16 | 149389218 |
| 17 | 485064009 |
| 18 | 1574993356 |
| 19 | 5113971944 |
| 20 | 16604963593 |
| 21 | 53915979657 |
| 22 | 175064088671 |