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 | 6 |
| 2 | 120 |
| 3 | 840 |
| 4 | 8064 |
| 5 | 4224 |
| 6 | 2196480 |
| 7 | 199680 |
| 8 | 5013504 |
| 9 | 74088448 |
| 10 | 1568931840 |
| 11 | 1899233280 |
| 12 | 2411724800 |
| 13 | 2831155200 |
| 14 | 8757706752 |
| 15 | 6968215339008 |
| 16 | 76890652016640 |
| 17 | 1488206168064 |
| 18 | 289223097712640 |
| 19 | 74371653697536 |
| 20 | 2197648866017280 |
| 21 | 10176804748787712 |
| 22 | 29785769996451840 |