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 | 2 |
| 2 | 576 |
| 3 | 17496 |
| 4 | 204800 |
| 5 | 1406250 |
| 6 | 6858432 |
| 7 | 26353376 |
| 8 | 84934656 |
| 9 | 239148450 |
| 10 | 605000000 |
| 11 | 1403076312 |
| 12 | 3027787776 |
| 13 | 6149354666 |
| 14 | 11859019200 |
| 15 | 21870000000 |
| 16 | 38788923392 |
| 17 | 66474865026 |
| 18 | 110505715776 |
| 19 | 178774347800 |
| 20 | 282240000000 |