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 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 100 |
| 6 | 492 |
| 7 | 1764 |
| 8 | 8592 |
| 9 | 71208 |
| 10 | 395520 |
| 11 | 1679480 |
| 12 | 9313128 |
| 13 | 72154030 |
| 14 | 420375872 |
| 15 | 1625653650 |