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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 48 |
| 4 | 576 |
| 5 | 3840 |
| 6 | 19200 |
| 7 | 80640 |
| 8 | 301056 |
| 9 | 1032192 |
| 10 | 3317760 |
| 11 | 10137600 |
| 12 | 29736960 |
| 13 | 84344832 |
| 14 | 232587264 |
| 15 | 626196480 |
| 16 | 1651507200 |
| 17 | 4278190080 |
| 18 | 10909384704 |
| 19 | 27433893888 |
| 20 | 68136468480 |
| 21 | 167352729600 |
| 22 | 406931374080 |
| 23 | 980510834688 |
| 24 | 2343038877696 |
| 25 | 5556613939200 |