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 | 1 |
| 3 | 2 |
| 4 | 12 |
| 5 | 288 |
| 6 | 34560 |
| 7 | 48 |
| 8 | 241920 |
| 9 | 6 |
| 10 | 2177280 |
| 11 | 7900913664000 |
| 12 | 315379190543155200000 |
| 13 | 658409472000 |
| 14 | 4099929477061017600000 |
| 15 | 47029248000 |
| 16 | 61498942155915264000000 |
| 17 | 2939328000 |
| 18 | 1045482016650559488000000 |
| 19 | 163296000 |