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 | 3 |
| 2 | 9 |
| 3 | 37 |
| 4 | 233 |
| 5 | 2254 |
| 6 | 34342 |
| 7 | 827262 |
| 8 | 31730508 |
| 9 | 1943441460 |
| 10 | 190609515540 |
| 11 | 29988517246560 |
| 12 | 7579307667005280 |
| 13 | 3080578207713982560 |
| 14 | 2015291663362285214400 |
| 15 | 2123462159890867147060800 |