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 | 5 |
| 3 | 53 |
| 4 | 862 |
| 5 | 19024 |
| 6 | 531520 |
| 7 | 17991630 |
| 8 | 715803832 |
| 9 | 32740331784 |
| 10 | 1692869465304 |
| 11 | 97648275936672 |
| 12 | 6216826224534624 |
| 13 | 433030023365176704 |
| 14 | 32757854472395131776 |
| 15 | 2674517780432621462640 |
| 16 | 234408432378333868580736 |
| 17 | 21951787708820941049727360 |