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 | 3 |
| 4 | 7 |
| 5 | 22 |
| 6 | 76 |
| 7 | 290 |
| 8 | 1018 |
| 9 | 3715 |
| 10 | 11068 |
| 11 | 24289 |
| 12 | 102642 |
| 13 | 163176 |
| 14 | 527675 |
| 15 | 1569567 |
| 16 | 2929322 |
| 17 | 4752512 |
| 18 | 21006062 |
| 19 | 24293375 |
| 20 | 95578494 |
| 21 | 205091895 |