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 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 12 |
| 5 | 28 |
| 6 | 94 |
| 7 | 298 |
| 8 | 1044 |
| 9 | 3658 |
| 10 | 13164 |
| 11 | 47710 |
| 12 | 174948 |
| 13 | 645436 |
| 14 | 2397342 |
| 15 | 8948416 |
| 16 | 33556500 |
| 17 | 126324496 |
| 18 | 477225962 |
| 19 | 1808414182 |
| 20 | 6871973952 |
| 21 | 26178873448 |
| 22 | 99955697946 |
| 23 | 382438918234 |
| 24 | 1466015854100 |
| 25 | 5629499869780 |