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 | 1 |
| 2 | 6 |
| 3 | 24 |
| 4 | 120 |
| 5 | 672 |
| 6 | 4320 |
| 7 | 26208 |
| 8 | 30240 |
| 9 | 524160 |
| 10 | 2178540 |
| 11 | 8714160 |
| 12 | 8910720 |
| 13 | 17428320 |
| 14 | 45532800 |
| 15 | 132723360 |
| 16 | 208565280 |
| 17 | 240589440 |
| 18 | 470564640 |
| 19 | 668304000 |
| 20 | 1307124000 |
| 21 | 5228496000 |
| 22 | 10805558400 |
| 23 | 14182439040 |
| 24 | 31998395520 |
| 25 | 159991977600 |