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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 20 |
| 7 | 48 |
| 8 | 115 |
| 9 | 285 |
| 10 | 715 |
| 11 | 1826 |
| 12 | 4711 |
| 13 | 12303 |
| 14 | 32387 |
| 15 | 85964 |
| 16 | 229662 |
| 17 | 617300 |
| 18 | 1667787 |
| 19 | 4527290 |
| 20 | 12340688 |
| 21 | 33766612 |
| 22 | 92707834 |
| 23 | 255329106 |