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 | 3 |
| 3 | 10 |
| 4 | 25 |
| 5 | 126 |
| 6 | 127 |
| 7 | 1716 |
| 8 | 2241 |
| 9 | 18469 |
| 10 | 15231 |
| 11 | 352716 |
| 12 | 36973 |
| 13 | 5200300 |
| 14 | 1799995 |
| 15 | 30333601 |
| 16 | 24331777 |
| 17 | 1166803110 |
| 18 | 12247363 |
| 19 | 17672631900 |
| 20 | 723276561 |