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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 6 |
| 5 | 30 |
| 6 | 60 |
| 7 | 420 |
| 8 | 840 |
| 9 | 7560 |
| 10 | 15120 |
| 11 | 166320 |
| 12 | 332640 |
| 13 | 4324320 |
| 14 | 8648640 |
| 15 | 129729600 |
| 16 | 259459200 |
| 17 | 4410806400 |
| 18 | 8821612800 |
| 19 | 167610643200 |
| 20 | 335221286400 |
| 21 | 7039647014400 |
| 22 | 14079294028800 |
| 23 | 323823762662400 |
| 24 | 647647525324800 |
| 25 | 16191188133120000 |
| 26 | 32382376266240000 |