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 | 4 |
| 3 | 40 |
| 4 | 1040 |
| 5 | 78240 |
| 6 | 18504256 |
| 7 | 14463224448 |
| 8 | 38544653734144 |
| 9 | 357896006503348736 |
| 10 | 11766320092785122862080 |
| 11 | 1387031702368547767793690624 |
| 12 | 592262859312707222259571097997312 |