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 | 3 |
| 5 | 12 |
| 6 | 10 |
| 7 | 20 |
| 8 | 35 |
| 9 | 280 |
| 10 | 252 |
| 11 | 2520 |
| 12 | 2310 |
| 13 | 27720 |
| 14 | 25740 |
| 15 | 24024 |
| 16 | 45045 |
| 17 | 720720 |
| 18 | 680680 |
| 19 | 4084080 |
| 20 | 3879876 |
| 21 | 739024 |
| 22 | 235144 |
| 23 | 5173168 |
| 24 | 14872858 |
| 25 | 356948592 |
| 26 | 343219800 |
| 27 | 2974571600 |
| 28 | 2868336900 |
| 29 | 80313433200 |
| 30 | 77636318760 |