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 | 1344 |
| 3 | 12960 |
| 4 | 118584 |
| 5 | 1004184 |
| 6 | 8250912 |
| 7 | 66210264 |
| 8 | 522241560 |
| 9 | 4063962024 |
| 10 | 31282792704 |
| 11 | 238663638432 |
| 12 | 1807307152056 |
| 13 | 13599932970888 |
| 14 | 101786388133320 |
| 15 | 758232651966984 |
| 16 | 5625079743143376 |
| 17 | 41579318178922608 |
| 18 | 306353541215271960 |