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 | 2 |
| 2 | 12 |
| 3 | 208 |
| 4 | 6608 |
| 5 | 438912 |
| 6 | 38672832 |
| 7 | 5956592640 |
| 8 | 1035058952448 |
| 9 | 288405058560000 |
| 10 | 83042522104507392 |
| 11 | 36519438671549890560 |
| 12 | 15719007594987094364160 |
| 13 | 10017433660808198506414080 |