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 | 2 |
| 2 | 4 |
| 3 | 14 |
| 4 | 56 |
| 5 | 282 |
| 6 | 1692 |
| 7 | 11846 |
| 8 | 94768 |
| 9 | 852914 |
| 10 | 8529140 |
| 11 | 93820542 |
| 12 | 1125846504 |
| 13 | 14636004554 |
| 14 | 204904063756 |
| 15 | 3073560956342 |
| 16 | 49176975301472 |
| 17 | 836008580125026 |
| 18 | 15048154442250468 |
| 19 | 285914934402758894 |
| 20 | 5718298688055177880 |
| 21 | 120084272449158735482 |
| 22 | 2641853993881492180604 |