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 | 28 |
| 4 | 120 |
| 5 | 496 |
| 6 | 672 |
| 7 | 30240 |
| 8 | 32760 |
| 9 | 523776 |
| 10 | 2178540 |
| 11 | 23569920 |
| 12 | 33550336 |
| 13 | 45532800 |
| 14 | 142990848 |
| 15 | 459818240 |
| 16 | 1379454720 |
| 17 | 1476304896 |
| 18 | 8589869056 |
| 19 | 14182439040 |
| 20 | 31998395520 |
| 21 | 43861478400 |
| 22 | 51001180160 |
| 23 | 66433720320 |
| 24 | 137438691328 |
| 25 | 153003540480 |
| 26 | 403031236608 |
| 27 | 518666803200 |