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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 24 |
| 5 | 324 |
| 6 | 3600 |
| 7 | 38148 |
| 8 | 398112 |
| 9 | 4132596 |
| 10 | 42818208 |
| 11 | 443356212 |
| 12 | 4589665248 |
| 13 | 47509091508 |
| 14 | 491769434400 |
| 15 | 5090291998452 |
| 16 | 52689326584800 |
| 17 | 545383755284532 |
| 18 | 5645229662006688 |
| 19 | 58433377222329972 |
| 20 | 604839778633231200 |
| 21 | 6260653947359090868 |
| 22 | 64803587809297981728 |