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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 420 |
| 8 | 3360 |
| 9 | 30240 |
| 10 | 403200 |
| 11 | 4019400 |
| 12 | 80166240 |
| 13 | 965284320 |
| 14 | 12173441280 |
| 15 | 162850287600 |
| 16 | 2428557331200 |
| 17 | 32123543612160 |
| 18 | 534678700308480 |
| 19 | 8126981741380320 |
| 20 | 128338880777251200 |
| 21 | 2080312367956502400 |
| 22 | 36351373041072122880 |
| 23 | 606331931399062693440 |